The following tests come from a document called "You can smelt too" by J.S. Wisdom. I have included the list of lab equipment needed and the chemicals for performing the tests, so you can create your own test kit. A few of these tests are scattered through out the forum threads, but most are not available, certainly not in one place that I have found, so I decided to share my good fortune. I will have to post this in two parts because of the number of tests.
QUICK QUALITATIVE ANALYSIS
"METHOD OF PROCEDURE"
Simply take your rock or ore and powder up a little of it as fine as possible; you then start right in at Test No. 1, then proceed to make each additional test just as given until you have completed your analysis for all the elements covered. Results: If any of the elements covered are present in your rock or ore, you identify them AS YOU COME TO THEM.
TEST EQUIPMENT (Laboratory Supplies )
1 Alcohol Lamp with wick; small 2 ounce best size for our use.
1 Blowpipe; just common plain brass is as good as any.
1 Platinum Wire, with glass holder; for making bead tests.
Porcelain Mortar and Pestle; for powdering up fusions.
Small Glass Funnel; small 2" top for filtering solutions.
Package 100 Filter Papers; round 3" or smaller best size.
Pair Tweezers; for handling tin or small objects.
Charcoal Blocks (sticks) for making fusions and color tests.
Small Porcelain (evaporating) dishes; #000 best size.
Test Tubes for chemical tests; 1/2" by 4" the best size.
1 One ounce glass stoppered bottle for hydrochloric acid,
1 One ounce glass stoppered bottle for nitric acid.
1 One ounce glass stoppered bottle for sulphuric acid.
1 One ounce screw-cap bottle for dimethylglyoxime solution.
1 One ounce screw-cap bottle for cacothelin solution,
1 One ounce screw-cap bottle for strong ammonia.
1 One ounce screw-cap bottle for silver nitrate solution.
1 One ounce screw-cap bottle for cobalt nitrate solution.
1 One ounce screw-cap bottle for sodium sulfide solution.
1 One ounce screw-cap bottle for prepared "Charcoal Flux".
CHEMICALS AND REAGENTS
Hydrochloric acid (CP).
Strong Ammonia.
Nitric Acid (CP).
Pure Grain Alcohol
Sulphuric Acid (CP) (or Acetone, see later)
Acetic Acid (Glacial)
Hydrogen Peroxide.
Denatured Alcohol; for operating the Alcohol Lamp,
Pure Distilled Water to prepare Reagent Solutions.
(Dry Chemicals and Powders)
Sodium Carbonate
Powdered Borax
Charcoal Powder
Pure Tin Metal
Zinc Metal Powder.
Pure Sulphur; sublimed.
Pottassium Iodide.
Potassium Nitrate
Potassium Hydroxide.
(Caustic Potash)
Potassium Ferrocyanide.
Potassium Pyrosulphate.
Potassium Chlorate.
Tannic Acid Powder
Ammonium Carbonate
Pyrolusite (MnO)
Sodium Hydroxide.
(Caustic Soda)
Sodium Nitrate.
Sodium Sulfide.
Cobalt Nitrate
Lead Acetate
Salt of Phosphorous.
Silver Nitrate.
Dymethylglyoxime,
Cacothelin,
SOLUTIONS TO BE MADE AT HOME
1. MATERIALS: The following solutions are all made up at home by using Dry Chemicals or Powders as listed on previous page.
2. PURE WATER: In all cases where solutions are to be prepared with water we should use pure distilled water
SILVER NITRATE SOLUTION: To prepare.
1. Fill an ounce bottle about half full of pure distilled water.
2. Add silver nitrate crystals equal to 2 or 3 grains of rice.
3. Shake bottle to help dissolve. This keeps for a long time.
CACOTHELIN SOLUTION: To prepare - for Tin Test.
1. Fill one ounce bottle about 1/2 full of pure water.
2. Add Cacothelin powder equal to about 2 or 3 navy beans.
3. Shake bottle to help dissolve .
STABILITY: Keeps well; but as use only 1 drop per tin test 1/2 ounce lasts long time; so if stood over three months check stability before testing unknown ores. To check see Stannous Chloride below.
STANNOUS CHLORIDE: (Well Covered in Forum threads)
DIMETHYLGLYOXIME: To prepare solution (for nickel test ).
NOTE: Should be mixed with pure grain alcohol if possible: but we find acetone will do about as well.
1. Fill an ounce bottle about 1/2 full alcohol (or acetone).
2. Add dimethylglyoxime powder equal to 2 or 3 navy beans.
3. Shake bottle to help dissolve (all may not dissolve^ o.k.)
COBALT NITRATE : Dissolve crystals equal to about 2 or 3 navy beans in 1/2 ounce of pure water. This is seldom used.
SODIUM SULPHATE; Dissolve crystals equal to about 2 or 3 navy beans in 1/2 ounce of pure water. This is seldom used.
The following are seldom used, and then only a few drops per test, and as they do not keep well in water solutions. It is best to mix in a test tube as needed.
AMMONIUM CARBONATE: Dissolve powder equal to about 1/2 the size of navy bean in 2 or 3 cc of pure water; shake to help dissolve.
POTASSIUM FERROCYANIDE: Dissolve flakes or powder equal to about 1/2 navy bean in 2 or 3 cc. of pure water.
CHARCOAL FLUX: This is not a solution, but as it is to be prepared at home, will be given here. This is used in all tests in Part Two where fusions are made, unless otherwise stated. It will work on practically all minerals, and thus save making up a different flux for each elements.
TO PREPARE: Mix thoroughly 4 volumes of powdered borax; 4 volumes of sodium carbonate (anhydrated, not common baking soda), and two volumes of powdered charcoal.
BISMUTH FLUX: This is another powder mixture to prepare at home. It is used in the testing of bismuth, or to distinguish bismuth from lead, as given in Test 25, Part Three. As it is used mostly as a confirmatory test, best to mix up as needed.
TO PREPARE: Mix equal parts potassium iodide and sulphur.
GYPSUM TABLETS: While "Bismuth Flux" may be successfully used on charcoal, the colors, especially for low-grade lead or bismuth, will show up much plainer on white gypsum tablet. Can also test antimony or arsenic by first blackening the tablet by holding in smoky flame, such as with match or coal-oil lamp.
ADDITIONAL EQUIPMENT
1. BOX - for "Field Test Kit"; this should be about 7" high by 7" wide by 12" long.
2. TEST TUBE STAND
3. TEST TUBE HOLDER
4. GYPSUM TABLETS: For purpose: see previous page. One should make up a couple dozen of these and have handy.
TO MAKE: 1. Get 2 or 3 pounds of plaster of Paris. 2. Now take a common window glass or any flat glass; make a frame around the same about 1/4" higher than glass. 3. Now take amount of material you think will take to fill space. 4. Add plenty of water and mix quickly, make into thin sloppy paste, 5. Pour on glass, then immediately take a long knife blade or piece of tin which will reach to both frames, and level off smooth; 6. When thoroughly set,-remove from the frame, mark oil and with hacksaw cut into blocks about 1" by 2-1/2"
5. CROCKERY: Some fusions made with flux may sometimes be made on crockery (or flat piece of chinaware, such as broken plate), and thus save charcoal blocks. Have peices about 1" square or may be larger.
6. HOLDER: For holding gypsum tablets, Crockery or small pieces of charcoal for heating with blowpipe. A: Take a piece of fairly heavy galvanized iron 1" wide by 5" long; bend up one end about 1/4". B: Take a piece of tin can about 2" square; bend one end of this about 1/4" to match longer
piece; cut where necessary and bend around long piece, so will slide back and forth on the long piece to act as a clamp to hold pieces of crockery, etc.
THE BLOWPIPE: ITS PURPOSE AND OPERATION
NOTE: The operation of the blowpipe is the only thing in our complete instructions which requires any skill or practice. Practice by following the instructions given below, and well worth the time spent as we may identify more elements in less time than by any other method; and also important in other tests where fusions are required. See "Tests Made on Charcoal" in Part Two.
OBJECT OF BLOWPIPE: To change the normal vertical lamp flame into a horizontal direction controlled by the operator, and thus concentrate the heat of the lamp flame into a long slender cone which may be directed against the assay or object to be tested.
FLAMES: It will be noticed there are two cones to the flame; each has a different color, and each one used for a different purpose:
A: An outer yellow cone which is called the Oxidizing Flame.
B. An inner blue cone which is called the Reducing Flame.
NOTE: Place a cardboard behind lamp to better see flame colors.
THE OXIDIZING FLAME: Some substances when Oxidized produce certain reactions, which is the object of this flame. The best point for oxidizing purposes is within the yellow flame just outside the blue cone with the blowpipe.
THE REDUCING FLAME: Some substances when melted, fused or reduced to the metallic state, produce certain reactions. The object of this flame is to fuse Or melt the object being tested. The best point for this purpose is just within the tip of the blue cone. We will also find some materials must be melted or fused with some flux before they will become soluble in water or acids, as explained in Part Two.
OPERATING THE BLOWPIPE
One of the first and most important things to learn in operating is to blow a steady blast of air, and thus produce a steady flame. The following will give the general idea, and may be learned with just a little practice. NOTE: The blast of air is not produced by the lungs, but by air held in the mouth,
replenished by a gulping action as explained below.
1. Place the mouthpiece between the lips; lips closed,
2. Now place tip of blowpipe just within flame of lamp, to the right hand side and just above the wick.'
3. Now distend or blow up cheeks.
4. Breathe in through the nose - never through the blowpipe!
5. Exhale, slowly, through the blowpipe (little air is required) at same time breathe naturally through the nose.
6. When more air needed in cheeks, make a sort of gulping action with cheeks. (Do not suck air through the blowpipe.)
7. Keep cheeks distended at all times, only the fraction of a second necessary for the gulping action; the object is to try to blow as steady a stream of air as possible, with as little break as possible. Practice extending time between gulping actions. Practice on making actual fusions and bead tests.
QUICK QUALITATIVE ANALYSIS THIRD EDITION-REVISED
"METHOD OF PROCEDURE"
TEST No. 1: For vanadium, manganese, sulphides, carbonates.
1. Use amount of powdered mineral equal to 3 grains of rice.
2. Plate above in clean porcelain evaporating dish.
3. Add 3 or 4 drops of cold strong hydrochloric acid.
RESULTS
A: If a sulfide the odor of sulphur, resembling rotten eggs may be detected, (We catch sulphides again later on).
B. If a carbonate, powder will effervesce (bubble or 'fizz"), NOTE; Sulphides will also sometimes effervesce, but can be distinguished by the odor of sulphur as given above.
C. If vanadium is present both powder and acid will turn red or brown quicklv. If so confirm by Test No. 60.
D. If manganese (all black ores) solution will be a greenish-black. If so, confirm by Test No, 39, Part Three.
NOTE: If there is, or is not, a reaction above, use same dish and powdered mineral for next Test No. 2.
TEST No. 2: For molybdenum-lead or molybdenum-oxide,
1. Use same dish and powdered mineral from test No.l above.
2. Add 1 cc or slightly more strong hydrochloric acid.
3. Boil over lamp flame; while boiling watch for blue or green stain on dish; boil to dry if necessany.
4. Remove dish from flame and let set for a few minutes to cool.
RESULTS NO 1: Blue stain on dish , hot or cold , is positive test for Mo Pb ( Wulfenite) or MoC (Molybdate), A green stain in dish indicates one of the above may be present. If so, confirm by Test 41 Part Three which will prove yes or no,
RESULTS NO . 2: If no blue or green above test is complete as no Mo Pb or MoO present, so proceed' with Test 3 below. But if blue or green see 4 previous page to find if MoPb or MoO.
NOTE: If there is, or is not, a reaction above, use same dish and powdered mineral for next Test No. 3 below.
TEST No. 3: For, tellurium, or tungsten; and and all ores.
1. Use same dish and powdered mineral from Test No, 2 above.
2. Add 2 cc hydrochloric acid; boil slightly over lamp flame.
3. Remove from flame and while hot add small piece tinfoil.
RESULTS No. 1 for tellurium: If much tellurium is present solution will turn black; if but little Te. just a dark solution around tin. In either case confirm by Test 54„ NOTE: The above is dark solution- not coating on tin. Now continue test for tungsten, as follows
4. Place dish back over lamp flame and boil until solution changes colonthen a little longer. Do not boil to dry. RESULTS No. 2 for tungsten: A blue solution is a positive test for tungsten; color may not show up until cold, depends on grade of ore; solution may first be red, but will tarn blue
on standing. See Test 58 Part Three. NOTE: MoO or Mo Pb may also give a red color, but will not turn blue on standing.
TEST No. 4: For tin. Any ore or metal. Very positive test.
1. Place powdered mineral size 2 or 3 grains of rice in dish.
2. Add powdered zinc metal of about equal quantity.
3. Add 8 or 10 drops hydrochloric acid ( this is Test Solution)
4. Place 2 or 3 drops of above Test Solution in another dish.
5. Add 1 or 2 drips of cacothelin solution.
RESULTS: A pale to dark purple spot if tin is present; the darker the color the more tin. This is a very positive test, even for very small quantities of tin, and may be made semi-quantitative by making test on spot paper as given below.
NOTE: If no sign of purple color above, skip the following:
1, Place a piece of filter paper on clean piece of glass,
2, Place i drop of Test Solution above in center of paper.
3, Add i drop of cacothelin solution in center of paper.
TEST NO. 4 (contd.) For tin.
RESULTS: A small pale-purple spot if very low grade ore. A large pale-purple spot, or a small dark-purple spot if fair grade ore. If high grade ore the spot will be dark-purple and at least size of a dime. By using same amount of powdered mineral and comparing with a sample of known percentage, a fairly accurate percentage of the unknown may be estimated.
TEST NO. 5: NOTE: This is a "master test" by which we catch from one solution below the following 11 elements: sulphur, copper, nickel, lead, thallium, bismuth, cobalt, tellurium, molybdenumsulphide, arsenic, silver. ( in the order listed)
NOTE: Results Nos. 1-2 and 3 below are not intended as positive tests, but are given to show what they indicate if present.
TO PREPARE TEST SOLUTION
1. Place 2 cc of strong nitric acid in a clean test tube.
2. Add powdered mineral equal to about one large navy bean.
3. Boil about 3 minutes; a little longer rather than less.
4. Remove from flame and let set about 2 minutes or so.
RESULTS No. 1: A spungy mass rising to top of the solution shows sulphides are present. Confirm by Test No. 1.
RESULTS No. 2: Green solution indicates copper or nickel or both. Confirm nickel by Test 6; copper by test 14.
5. Now add 3 cc pure water free of chlorine (see page in Part Three). Heat slowly and carefully just to boiling.
RESULTS No.3: A rose-color indicates cobalt; See Test 8.
NOTE: We will call this test solution S for reference in making the following 9 tests from this one solution.
TEST NO.6; For Nickel (for any and all ores). Spot test.
1. Place a piece of filter paper on a piece of clean glass.
2. Place 1 drop dimethylglyoxime solution in center of paper.
3. Add I drop of Test Solution 5 above to center of damp spot.
4. Add 1 drop of strong ammonia to center of above spot.
RESULTS: A red or rose color, which will not fade, is a positive test for nickel. (Iron will sometimes give a red or rose, but will fade out within a few minutes). The brighter the color the more nickel present, (see Test 42, Part Three).
NOTE: The color, especially for low grade nickel, can usually be brought out plainer if wait until the paper is dry and then add another drop of strong ammonia to center of paper.
TEST NO. 7. Lead, thallium, bismuth, or bismuth and lead.
1. Place 2 drops of test solution 5 in an evaporating dish.
2. Add about 6 or 8 drops plain water to dilute solution.
3. Add few crystals potassium iodide (KI.); see FOOTNOTE.
RESULTS
A: For lead or thallium: If either present even in small quantities, there will be a yellow or brownish precipitate. Confirm lead by Test 25. Confirm thallium by Test II-J.
CAUTION: Do not mistake a yellow solution for precipitate; if a precipitate it will settle out in bottom of the dish, which may be plainer seen after has set for a few minutes.
B. For bismuth: If much bismuth solution will turn black.
NOTE: This is not a positive test for bismuth, but merely indicative, as too strong acid, or other impurities will sometimes cause solution to turn black with potassium iodide. But if there is a black color, and to be sure and not overlook bismuth, confirm by Test 25, Part Three.
C. For both lead and bismuth sometimes found in same ore. If much bismuth solution may first be black, but on setting for a few minutes black color will leave in which the yellow or brown precipitate of lead may easily be seen in dish. Confirm either lead or bismuth by Test 25, Part Three.
TEST NO. 8: for cobalt (any and all ores).
1. Place 10 drops test solution 5 in clean evaporating dish.
2. Boil over lamp flame until dry; just a little longer.
3. Remove from flame, while hot add 1 cc hydrochloric acid.
RESULTS: a green solution is a positive test for cobalt, any and all ores; but may confirm by Test No. 16.
NOTE: Use same dish and acid for next Test No. 9.
TEST NO. 9; For tellurium, molybdenum sulphide, arsenic.
1. Use same dish and acid from previous Test No. 8.
2. Place over lamp flame and boil off 1/2 solution.
3. Remove from flame and immediately drop in small piece of pure tinfoil while hot; tip dish and slowly rotate once.
RESULTS
A: For tellurium: If much Te. solution will turn black. If but little Te. a dark color around tin; Watch closely!
TEST NO. 9: (contd.) For tellurium, molybdenum sulphide, arsenic:
B. For molybdenum sulphide: Blue stain on dish is positive test for MoS, needs no confirming. There will also be a red or rose-colored solution after dish has set for some time.
C. For arsenic: A brown film or scales on dish or floating on solution indicates arsenic. Confirm by TestNo.ll-A.
TEST NO. 10: For silver, or lead, or both if together.
1. Now take tube with remaining test solution 5.
2. Warm slightly; filter into clean test tube, let cool.
3. When solution cold add 1 or 2 drops hydrochloric acid.
RESULTS: A white "curdy" precipitate or mass, or a milky-white or opal-color, all indicate silver or lead or both; color depends upon amount of either or both present.
NOTE: To determine if silver or lead or both, see pages Part Three, and proceed as given there.
TESTS MADE ON CHARCOAL
TEST FOR : As. Sb. Cd. Se. Os. Ge. S. Pb. Bi. Tl. Te. Sn. Zn. Al. Mg. Au. Ag. (Fe.Ni.Co.).
TEST NO. 11: CHARCOAL - NO FLUX. (Tests made with blowpipe).
1. Use powdered mineral equal to 2 or 3 grains of rice.
2. Place on end of charcoal block (stick).
3. Heat steadily and for some time in the Oxidizing Flame.
RESULTS: See, "Reactions to watch for" as listed below.
4. If no results in above, heat in the Reducing Flame
5. Now note if any reactions as listed below.
NOTE: For reactions of different elements see next page.
TEST NO. 12: CHARCOAL - WITH FLUX. (Tests made with blowpipe).
1. Use powdered mineral equal to 2 or 3 grains of rice.
2. - Mix with "Charcoal Flux" equal to a large navy bean.
3. Make into paste with drop of water; place on charcoal.
4. Fuse to liquid state with Reducing Flame, then, while hot, run knife blade under fusion, turn over then fuse some more; a good fusion is quite necessary.
RESULTS: The same as in Test 11, and as listed below; some minerals which show little or no reaction without flux, may show a good reaction with flux; so both should be tried.
NOTE: For reaction of different elements see next page.
REACTIONS TO WATCH FOR
(Both with and without flux)
A; SUBLIMATE: (Coating). If heavy or light; color; if near or distant from assay; color while hot color when cold.
B: VOLATILITY: If easy, fairly easy, or non-volatile; first in Oxidizing Flame; then try Reducing Flame,
C; FLAME COLORS: Note if any change given off by the assay itself; or sublimate if touched with the Reducing Flame.
D: Touch sublimate with R.F. (for instant only); note if a change in color, or colored flame; if so, what.
E: ODORS: Note if any; example: garlic-like odor indicates As. A radish-like odor indicates selenium, etc.
F: .SMOKE OR FUMES: Example: heavy white smoke indicates Sb. Fumes smart the eyes (good test) indicates Os. etc.
G: ASSAY: Note if any change in color or appearance; if so, what? Inspect hot; inspect cold.
H: FUSIBILITY: (No Flux): If easy, fairly easy, or hard to fuse, or infusible. Important in testing for aluminum or magnesium with cobalt nitrate; See Test 38 Part Three,
I: GLOBULES: Note if any small metallic beads; if so, their color, hot and cold.
J: SECTILITY: If globules are easy, fairly easy, or hard to cut with knife, (Such as Pb. Ag. Sn. Bi. e t c . ).
K: MALLEABILITY: If globules will flatten, or are brittle.
L: MAGNETISM: Test powder with magnet before heating; then after heating in R.F. Test mass after fusing with flux.
NOTE: AFTER FUSING WITH FLUX SAVE FUSION FOR TEST NO. 13.
REACTIONS ON CHARCOAL ( W i t h or Without Flux; try each ; see previous page)
NOTE: First 7 elements are positive; need no confirming.
A: White light coat, distant assay. Very volatile. Garlic-like odor. (Odor is most positive test) — As.
B: White heavy coat, near assay, bluish out-border. Volatile White smoke - continues after heating ' Sb.
C: Red or brown coat with bright blue border — - Cd.
D; Steel-gray coating, red outer-border. Volatile, If coat touched with R.F. an azure-blue flame; a peculiar radish-like odor; odor is positive test. - Se.
E: Sharp bromine-like odor; fumes smart the eyes Os.
F: First, pure white coat near assay, if more heat moves further out, assumes greenish to brownish or lemon color; if examined with lense coat presents a glazed or enamel-like surface. Small milk-white globules scattered on charcoal near the assay Ge.
G: A very sharp pungent suffocating odor --- D,
NOTE: Following are indicative; should be confirmed.
H: Yellow coating near assay; non-volatile. Small metallic beads on assay; malleable, easy cut •- — Pb.
I: Yellow coat near assay; non-volatile. May be small metallic beads on assay; harder to cut than lead Bi. (Confirm either lead or bismuth by test No. 25) '
J: A slight white coat and an INTENSE green flame Tl. (Confirm thallium by Test No.7)
K. Heavy white coat, blue out-border with yellowish cast, black band between; all burn off with bluish flame, which is also yielded by the assay itself Te. (Confirm tellarium by Test No.3; most positive)
L: Yellow hot, white cold coating; non-volatile, small metallic globules. If coating moistened with cobalt nitrate solution and assay strongly heated coating will - become bluish-green when cold
M: Yellow hot, white cold with blue border. Non-volatile. No metallic globules. If coating moistened as above and reheated, coat becomes a bright green - — Zn. {Confirm Zinc by Test 60, Part Three)
N: No flux; Infusible. If heated then assay moistened as in L. above and reheated, assay becomes green — - Al.
O: No flux; infusible. If heated then assay moistened as in L. above and reheated, assay becomes pink Mg. (Confirm magnesium by Test No. 38, Part Three)
P: With flux: red metallic looking mass or specks — - Cu. (Confirm copper by Test 14; most positive test)
Q: Yellow, soft, malleable globule, bead or button ---— Au. (Confirm Gold by Test 34, Part Three)
R: White malleable globule, beads or button - — Ag. (Confirm silver by Test 52, Part Three)
S: A magnetic residue after heating in R.F. and let cool indicates either iron, nickel, or cobalt present.
TEST 13-A: For Cb., Ti. - any ore. (Also W. Mo. V. Co.).
ALL these but Cb. and Ti. should have been found, if present, in previous tests, so main object here is to cover Cb. and Ti. However, reactions for others will also be given here to watch for. Some colors may occur quite soon, some only on standing until cold or longer -so watch both,
TO TEST: use same fusion from Test 12, or make a new one.
1. Pulverize fusion from. Test 12, or the new one.
2. Place in clean test tube with 2 cc hydrochloric acid.
3. Add a small piece of metallic tin (Tinfoil best).
4. Boil till solution changes color; then a little longer.
NOTE: Add more tin if solution does not change color,
RESULTS
A: Light-blue solution indicates columbium; may not show up until cold or longer. Color brighter if let set few minutes then add powdered zinc metal equal to 2 grains rice.
B. Dark-blue solution indicates tungsten. To determine if W. or Cb.: W. gives a blue solution in Test 3, Cb. will not.
C; A lavender solution indicates Tl. Confirm by Test 57.
TEST NO. 13-A: (contd.) For Cb., Ti. - any ore. (Also W.Mo.V.Co.).
D. A red or rose solution if Mo. present. Positive test.
E. A green solution indicates V. or Co. Confirm V. by tests 1-17 and 60. Confirm Co. by tests 5-8 and 17,
NOTE; In above, charcoal may remain in suspension and thus make colors hard to distinguish; if so, may proceed as in Test 13-B for Cb. and Ti. If no color above can skip 13-B.
TEST NO. 13-B: Special test for Cb. and Ti. If in doubt above.
1. Place a piece of chinaware in adjustable holder.
2. Place on same powdered borax {or borax glass best) equal to about 1/2 size of common pea (more or less).
3. Add powdered mineral equal to about 2 grains of rice.
4. Add sodium hydroxide (pellet best) equal 1/2 size pea.
5. Fuse well with blowpipe, while hot turn over with knife blade and fuse again. A good fusion is necessary.
6. While hot remove fusion and crush in porcelain mortar.
7. Place in test tube with 2 cc strong hydrochloric acid.
8. Add 1 or 2 small pieces of metallic tin (tinfoil best).
9. Boil until solution changes color; then a little longer.
RESULTS: Same as in Test I3-A, but colors plainer seen. Let set a few minutes then add zinc powder size 2 grains rice.
TEST NO. 14: For copper, any ore; most positive test for Cu.
1. Place small piece scrap charcoal in adjustable holder,
2. Place on same small piece mineral size of match head.
3. Heat to redness in oxidizing flame of blowpipe.
4. Add 1 drop hydrochloric acid; now reheat with blowpipe.
RESULTS: a blue or green flame if any copper present.
TEST NO. 15: For mercury (Hg). Method of procedure,
NOTE: Cinnabar is only main ore; it is very characteristic color (usually vermilion-red or scarlet; very few rocks even resemble it. Should have known sample cinnabar, then test for Hg. only when your rock resembles same, in which case see Test 40 Part Three, and proceed as given there.
BORAX AND SALT OF PHOSPHOROUS BEADS General Information
BORAX BEADS: Made on platinum wire, as follows:
1. Heat end of platinum wire in flame of the alcohol lamp.
2. While hot quickly touch to borax powder.
3. Reheat in lamp flame until fusion stops,
4. While hot touch again to borax, then reheat; repeat this until bead is about the size of a small grain of rice.
5. Now heat with blowpipe until bead clear and transparent,
6. While hot touch to few specks of roasted powdered mineral.
7. Heat for some time in the O.F. (Oxidizing Flame) of blowpipe. Note the color, if any, while hot and when cold.
8. Now heat in R.F. (Reducing Flame): note color, hot, cold.
9. If no color, add few more specks of mineral; try again.
Repeat this until bead is saturated (opaque)
RESULTS: If an appreciable amount of element is present a point will be reached where color v. ill show up as listed on following page. NOTE: In making or heating bead, hold wire horizontal to remove bead hold wire vertical, then heat.
SALT OF PHOSPHOROUS BEADS: These are made same as Borax beads, except salt of phosphorous is more liquid when hot, and thus harder to hold on the wire; beads must be built up slower, using less material at a time. In building up bead, hold higher above lamp flame, then gradually lower.
AMOUNT OF MINERAL TO USE: From a very few specks in most cases, up to the amount where the bead is saturated (opaque). This depends upon kind of mineral, quality and impurities. Generally speaking just a few specks are sufficient.
ROAST MINERALS FIRST: All minerals should first be roasted on charcoal before making bead tests, otherwise bead may be dark or brown.
TO ROAST: Place a little mineral on charcoal, heat to red in O.F. then in R.F. ;wind up by heating in the O.F. -CAUTION: Note results, if any, for following reasons:
RESULTS: If any smoke or coating on charcoal in roasting, continue to heat in O.F. then in R.F. until all smoke and sublimate cease; otherwise volatile minerals will alloy with the platinum; this will not "salt" the wire, or cause any color in future tests, but will make the wire brittle, and cause
it to break oil and thus waste the valuable wire.
CAUTION: A clean wire must always be used, or may "salt" the wire from a previous test, that is providing a color was obtained in a previous test; if no color in previous test then need not be as no danger of "salting".
TO TEST 'WIRE: Make a bead in usual way (without using any mineral). Heat in O.F. then in R.F.
RESULTS: If no color shows up the wire is ok; but if color then clean wire.
TO CLEAN WIRE: Boil in a little hydrochloric acid then wash well by shaking back and forth in clean water.
NOTE: For bead colors of the elements see following:
BEAD COLORS OF THE ELEMENTS
-With Borax and Salt of Phosphorous -
ABBREVIATIONS : Yel. means yellow; Cls. means colorless. O.F. is oxidizing flame.
R.F. is reducing flame (blowpipe).
NOTE: All these elements but U. and Di. were covered in previous tests; but colors given here will help to confirm.
TEST NO. 16: BORAX BEAD COLORS
CHROMIUM - Cr. O.F.: Yel. hot; green cold. R.F.: Green hot; green cold. Confirm by Test 27 as given in Part Three.
VANADIUM - V. O.F.: Yel. hot; green cold. R.F.: Green hot; green cold. Confirm by Test 60 (Any ore containing V. should also be assayed
for uranium as they many times occur in same ore).
URANIUM - U. O.F. : Yel. hot; Ylsh-green cold. " R.F.: Green hot; green cold. Confirm by Test 59, but above is always worthy of assay.
DIDYMIUM - Di.
NOTE: Is a mixture of neodymium(Nd) and. Praseodymium ( Pr.) O.F.: Rose Hot; rose cold. R.F.: Rose hot; rose cold,
We have no confirmatory test for Di; usually none needed.
COBALT - Co. O.F. Blue hot; blue cold. R.F. Blue hot: blue cold. This is a very positive test; but may confirm by Test 8.
IRON - Fe. O.F. Yel. hot; cls. cold. R.F.: Yel. hot; cls. cold. NOTE: May be pale-green cold; see Test 36 in Part Three.
TEST NO. 17: SALT OF PHOSPHOROUS BEADS
NOTE: Borax beads are best for practice, but salt of phosphorous covers more elements more accurate; so best to use. Confirm same as Borax above, unless otherwise stated below.
CHROMIUM - Cr. O.F.: Green hot; green cold. R.F.: Green hot; green cold.
VANADIUM - V. O.F.: Yel. hot; yel. cold. R.F. Green hot; green cold. NOTE; Yellow in O.F. when cold distinguishes V. from Cr.
URANIUM - U. O.F.: Yel. hot; yel-green cold. R.F. : Green hot; green cold.
MOLYBDENUM OXIDE - MoO. O.F.: Yel. hot; cls. cold. R.F.: Green hot; green cold. Confirm molybdenum oxide by test no. 2; most positive test.
COLUMBIUM – Cb O.F.: Yel. hot; Cls. cold. R.F. Brown hot; brown cold. Confirm by Test 13 -B; most positive test for columbium.
DIDYMIUM - Di. O.F.: Rose hot; rose cold. • R.F.: Rose hot; rose cold.
COBALT - Co. O.F. Blue hot; blue cold. R.F.: Blue hot; blue cold.
IRON - Fe. O.F.: Yel.hot; cls. cold. R.F. Yel.hot; cls. cold. Note: Iron with saturated bead may be pale-green cold.
SECOND PROCEDURE
TEST MADE ON CONCENTRATES
-General Information -
1. After completing our Qualitative Analysis on the crude ore, as given in previous pages, we then proceed to concentrate our rock in a gold pan, then re-check for the heavier elements, such as gold, silver, lead, bismuth, nickel, tin, tungsten, uranium, tantalum, columbium, platinum minerals,
etc., which due to their high value may be present in paying quantities, but did not catch in the first procedure on the crude ore due to small quantity material used in testing.
2. Note: If any sulphides or tellurium found in the first procedure, roast ore thoroughly before panning.
3. To Roast Ore: Place crushed or powdered ore in a metal container, such as an old frying-pan, pie tin or shovel, place over open flame, such as camp fire, stove with lid removed, or better in a blacksmith forge. Heat, and hold to a dull redness for 10 to 30 minutes, or until no more smoke or any sulphur fumes given off; keep stirring ore while roasting.
4. Another good method: For any and all rocks. Heat rock for some time, to red if possible, in camp fire, stove or in blacksmith forge; then stand back in case rock explodes and toss in bucket of cold water. This will help free rock of sulphides and tellurium, also reduce certain elements to the
metallic state, such as lead, bismuth, gold and silver tellurides, etc. Also make rock easier to pulverize later on.
5. To prepare ore for concentrating: Take a pound or more of your rock, crush in iron mortar or other means until all will pass through window screen, then place on a buckboard and with muller pulverize to flour fineness.
6. Buck-board: Any smooth flat piece of iron will do, such as old stove lid, but larger the iron, the quicker the work.
7. Muller: For rubbing or grinding ore on buck-board. Any piece of smooth flat iron will do; the bottom plate of an old discarded electric flat-iron is ideal for this purpose.
8. Panning: A 6 inch frying pan with handle cut off is a handy pan for lab. work. Fill an extra pan with water. Place powdered mineral in gold pan, fill with water, shake vigorously to settle heavy materials; now by lowering and raising pan in water, wash off lighter materials; stop and shake pan often; repeat this until only a spoonful or less remains.
9. Results: If any heavy concentrates in pan, especially if non-magnetic, as explained on this and following page, recheck for heavier elements as given in paragraph 1 above. Also check for gold and platinum minerals by tests 18 - 19 - 20 - 21.
GOLD AND THE PLATINUM GROUP MINERALS
- General Information -
1. Gold: The first thing to remember , and this will apply to old timers as well as greenhorns: While pure gold is always yellow it is seldom if ever found in the pure state in nature, but is always associated with other elements which may change its color; such as alloyed with silver or mercury, in which case it may have a bronzy white color; or in chemical combination with tellurium, in which it will look silver - white or gray; ir associated with iron oxides , in which it may be coated brown or red; or may be coated jet-black if found in manganese, and thus mistaken for black iron. So to make sure all concentrates should be checked for gold by chemical tests.
2. Platinum Minerals: There are 6 minerals known as the Platinum Group: Platinum , Palladium, Iridium, Osmium, Rhodium and Ruthenium, listed in the order of their frequency of occurence as well as uses. We seldom if ever find any one of these in the pure state in nature, but in practically all cases will find two or more alloyed together, and in some cases traces or more of all six. This greatly simplifies our work in their identification, in the following manner:
In practically every case each one will contain either Platinum or Palladium, or both. In Part Three we give tests for all 6 elements; while the tests for iridium, osmium, ruthenium, and rhodium are all fairly accurate on the pure elements, they are not always accurate as found in nature due to impurities; but the tests for Platinum and Palladium are always accurate in all cases, regardless of impurities , with the following results.
We first test for Platinum and Palladium only: If both of these are absent in our concentrates, and while there are possible exceptions, we can usually quite safely assume that none of the other 4 are present. If we find either Platinum or Palladium, or both, v\e then have our ore or concentrates assayed for Iridium and osmium as well as platinum and palladium. Rhodium and ruthenium usually occur in small quantities and are obtained as a by-product in the refining of other platinum minerals , and are seldom if ever paid for. The natural colors of platinum and palladium are silver-white or gray, but as found in nature, due to other impurities , they may tarnish black , resembling black iron, or may have a yellow or a bronzy cast resembling iron pyrites. For these reasons all heavy concentrates should always be tested for Pt. and Pd. regardless of color.
3. Characteristics : Gold , platinum and palladium are all quite soft and malleable ; may be cut with a knife and will flatten without breaking. Iridium is also somewhat malleable, but harder. The only other soft malleable elements occuring in nature are native silver, bismuth and copper, all of which can be easily eliminated as follows: Silver, copper, and bismuth are all soluble in nitric acid; gold and platinum are not soluble in any single acid, but are both soluble in Aqua Regia, so if your material dissolves in nitric acid you can be sure it is not gold or platinum. Palladium is somewhat soluble in nitric acid, giving a wine-red solution, and completely soluble in aqua regia , and thus, gold , platinum and palladium can all 3 be detected if present in any aqua regia solution by the four simple tests 18-19-20 and 21 as given on the following,
TESTS FOR GOLD - PLATINUM - PALLADIUM
TEST No. 18 : To prepare test solution for Au. Pt. Pd.
1. Pick out particles suspected of being Au. Pt. Pd. or use concentrates equal to about one navy bean or pea.
2. Place the above in a clean test tube.
3. Add 1 cc Nitric and 3 cc Hydrochloric Acid ( Aqua Regia)
4. Boil over lamp flame for at least 5 minutes or longer.
RESULTS : Gold, platinum or palladium, if present , are now in solution , from which we will make the following 3 tests.
NOTE: To become familiar with the various colors and other reactions in the following tests, one should first practice on known samples of gold, platinum and palladium,
TEST No. 19: For Gold - Au. Spot Test with stannous chloride.
1. Place a piece of filter paper on a clean piece of glass.
2. Place one drop of Test Solution 18 in center of paper.
3. Add one drop freshly prepared stannous chloride solution. ( To prepare solution see article 6, Part One).
RESULTS: If gold is present there will be a purple or rose colored spot when paper is dry; color depending on amount of gold present ; the darker the dolor the more Au. Color will show plainer , especially for low grade ores, if let paper dry then add another drop of stannous chloride solution.
TEST No. 20: For Platinum- Pt. with potassium iodide - K1 .
1. Place about 20 drops test solution 18 in evaporating dish.
2. Boil over lamp flame until dry; then just a little longer.
3. Let dish set few minutes to cool so will not break dish.
4. Add 3 or 4 cc plain water; reheat just to boiling.
5. Filter solution into another clean evaporating dish.
6. Add potassium iodide equal to about one grain of rice.
7. Warm solution slightly over lamp flame, watch, for color.
RESULTS: If Pt. is present the solution will turn a light or dark rose color, either at once or after set few minutes; the more Pt. present the quicker and darker the color. NOTE. Sulphides or other impurities may sometimes give a red color which may be mistaken for a rose, in which case proceed as follows: boil off say one-half solution to hasten evaporation, then let dish set until dry, then add few drops plain water. RESULTS: If Pt. a bright rose color; if sulphides or other impurities solution will be colorless. This is the most positive test for Pt. If solution appears red, add a few cc's plain water to better see rose color.
TEST No. 21: For Palladium - Pd. With Potassium Iodide. NOTE: If in above test for Pt., and upon adding KI and warming (lines 6 and 7), if Pd. present the solution will turn dark colored or black , depending upon Pd. present; the more Pd. the darker the color. There will also be a black precipitate in bottom of dish, which upon adding an excess of KI will disolve giving a wine-red color. However, the dark solution is the main test for Pd., otherwise a red color means nothing for reasons explained in test 20 for Pt.
PART THREE
INDIVIDUAL AND CONFIRMATORY TESTS
TEST NO. 22: Aluminum - Al.
NOTE: Mineral should be light colored, or become so on ignition: MUST BE INFUSIBLE: Test for fusibility first.
1. Place on charcoal piece size of 2 grains of rice.
2. Heat steadily on hottest part of the blowpipe flame.
3. Inspect with lens; note if fused even slightest on edge.
RESULTS: If any sign of fusion, test will not apply, as any fusion will turn blue with cobalt nitrate solution. If no sign of fusion, proceed with test:
4. Replace piece of mineral on charcoal.
5. Apply 1 drop of cobalt nitrate solution to assay.
6. Heat in hottest part of blowpipe flame; note results.
RESULTS: If assay turns blue indicates Al. but possibly zinc; check Zn. If no Zn. it proves presence of aluminum. If no blue by above test, proceed as follows:
7. Powder mineral: dampen with drop cobalt nitrate solution.
8. Heat in hottest part of blowpipe flame.
RESULTS: Same as results above.
TEST NO. 23: Antimony - Sb.
TEST A: Charcoal - No Flux (See Test 11).
1. Place on charcoal small piece about size 2 grains rice.
2. Heat steadily in the Oxidizing Flame of blowpipe.
RESULTS: Heavy white volatile sublimate near assay; white smoke; smoke may continue after heating ceased; smoke and sublimate is a positive test for antimony
TEST B: Charcoal - With Flux, (See Test 12).
1. Use powdered mineral equal to two grains of rice.
2. Mix with "Charcoal Flux" equal to two navy beans.
3. Heat and fuse in the Reducing Flame of the blowpipe.
RESULTS: Same as in Test A. (See Test 12 for reason why).
TEST No. 24: Arsenic - As.
TEST A: Charcoal - No Flux (Some arsenic minerals).
1. Use small piece of mineral size of 2 grains of rice.
2 . P l a c e on charcoal; heat in the Oxidizing Flame.
RESULTS: Light white sublimate, some distance from assay; very volatile; GARLIC-LIKE ODOR; positive test.
TEST B: Charcoal - With Flux (See Test 12).
1. Use powdered mineral equal to two grains of rice.
2. Mix with "Charcoal Flux" equal to large navy bean.
3. Dampen with water; place on charcoal block.
4. Heat and fuse in the Reducing Flame; note results.
RESULTS: Same as in Test A. (See Test 12 for reason why).
TEST NO. 25: Bismuth - Bi.
WITH BISMUTH FLUX: Equal parts potassium iodide and sulphur.
1. Place bismuth flux equal to about a large navy bean in a porcelain evaporating dish.
2. Add powdered mineral equal to about two grains of rice.
3. Dampen to thick paste with a drop of water and place on a charcoal block of gypsum tablet. (Gypsum tablet best for detecting small quantities of bismuth -easier to see).
4. Fuse thoroughly in the reducing flame of the blowpipe.
RESULTS: Yellow coating near assay, bright red border. This is most accurate test for even small quantities of Bi.
NOTE: This is also a good test for lead which gives a yellow coating near assay -no red border.
TEST NO. 26: Cadmium - Cd.
TEST: To detect 1% or less of cadmium even with much zinc. (Cadmium is found associated with some zinc ores)
1. Use powdered mineral equal to about two grains of rice.
2. Mix with sodium carbonate equal to about one navy bean.
3. Make into a thick paste with a drop of water.
4. Place on charcoal block and heat steadily in the reducing flame of the blowpipe.
RESULTS: Reddish-brown coating near the assay with a blue border; usually iridescent (Peacock) if only a little of the sublimate forms. Sometimes seen best when cold.
Note: Zinc being less volatile the white coating of Zn. forms only after continued heating. Check zinc by Test 61.
TEST NO. 27: Chromium - Cr.
TEST A: With salt of phosphorous bead.
Note: For making bead tests see instructions in Part Two.
1. Oxidizing Flame: Dirty-green hpt, emerald green when cold.
2. Reducing Flame: Dirty-green hot, emerald green when cold.
TEST B: Where iron, etc., interferes with the above test.
1. Place sodium carbonate, equal to one navy bean and same amount of potassium nitrate in an evaporating dish.
2. Add powdered mineral equal to about 2 grains of rice.
3. Mix above thoroughly and dampen with a drop of water.
4. Place on charcoal block and fuse thoroughly with blowpipe.
RESULTS: Fusion usually yellow if much chromium present.
5. Place 3 cc of water in a test tube and heat to boiling.
6. Add powdered fusion to water and reheat to boiling.
RESULTS: Chromium now in solution (usually yellow).
7. Filter solution into a clean test tube.
8. Add about 6 drops or so of glacial acetic acid.
9. Add a few small crystals of lead acetate. RESULTS: A yellow precipitate if much chromium present. To confirm: Shake tube and filter; let paper dry, then test precipitate with salt of phosphorous bead by Test A. above.
TEST NO. 28: Cobalt - Co.
TEST A: Made with either borax or salt of phosphorous beads.
1. Oxidizing Flame : Blue hot, blue cold.
2. Reducing Flame: Blue hot; blue cold.
TEST B: Quick test with nitric and hydrochloric acids.
1. Place about 1 cc nitric acid in an evaporating dish.
2. Add powdered mineral equal to about 2 grains of rice.
3. Boil to dry over lamp flame; remove and let dish cool.
4. Add about 1 cc hydrochloric acid; warm dish slightly.
RESULTS: A green solution if Co. Confirm by Test A above.
TEST No. 29: Columbium - Cb.
TEST: With borax fusion, hydrochloric acid and metallic tin.
1. Place borax powder size 2 navy beans in evaporating dish.
2. Add finely powdered mineral equal to about 2 grains rice.
3. Dampen with water, place on charcoal block, or chinaware.
4. Fuse thoroughly in the Reducing Flame of the blowpipe.
5. Turn over and fuse again. A good fusion is necessary.
6. Crush fusion and grind to powder in a porcelain mortar.
7. Place in test tube with 3 cc strong hydrochloric acid.
8. Add a small piece of pure metallic tin (Tinfoil best).
9. Boil until solution changes color; then a little longer. (Add extra tin if necessary to change color of solution).
RESULTS: A pale-blue solution if columbium is present. Color may not show up until solution is cold or longer. the colorlor may be brought out plainer if let dish set few minutes then add powdereded metallic zinc equal to about 2 grains rice.
NOTE: Tungsten will give a dark-blue solution in this test. To determine if Cb.. or W; Tungsten will give a blue color in Test 3, columbium will not, and thus their identification.
End Part 1
QUICK QUALITATIVE ANALYSIS
"METHOD OF PROCEDURE"
Simply take your rock or ore and powder up a little of it as fine as possible; you then start right in at Test No. 1, then proceed to make each additional test just as given until you have completed your analysis for all the elements covered. Results: If any of the elements covered are present in your rock or ore, you identify them AS YOU COME TO THEM.
TEST EQUIPMENT (Laboratory Supplies )
1 Alcohol Lamp with wick; small 2 ounce best size for our use.
1 Blowpipe; just common plain brass is as good as any.
1 Platinum Wire, with glass holder; for making bead tests.
Porcelain Mortar and Pestle; for powdering up fusions.
Small Glass Funnel; small 2" top for filtering solutions.
Package 100 Filter Papers; round 3" or smaller best size.
Pair Tweezers; for handling tin or small objects.
Charcoal Blocks (sticks) for making fusions and color tests.
Small Porcelain (evaporating) dishes; #000 best size.
Test Tubes for chemical tests; 1/2" by 4" the best size.
1 One ounce glass stoppered bottle for hydrochloric acid,
1 One ounce glass stoppered bottle for nitric acid.
1 One ounce glass stoppered bottle for sulphuric acid.
1 One ounce screw-cap bottle for dimethylglyoxime solution.
1 One ounce screw-cap bottle for cacothelin solution,
1 One ounce screw-cap bottle for strong ammonia.
1 One ounce screw-cap bottle for silver nitrate solution.
1 One ounce screw-cap bottle for cobalt nitrate solution.
1 One ounce screw-cap bottle for sodium sulfide solution.
1 One ounce screw-cap bottle for prepared "Charcoal Flux".
CHEMICALS AND REAGENTS
Hydrochloric acid (CP).
Strong Ammonia.
Nitric Acid (CP).
Pure Grain Alcohol
Sulphuric Acid (CP) (or Acetone, see later)
Acetic Acid (Glacial)
Hydrogen Peroxide.
Denatured Alcohol; for operating the Alcohol Lamp,
Pure Distilled Water to prepare Reagent Solutions.
(Dry Chemicals and Powders)
Sodium Carbonate
Powdered Borax
Charcoal Powder
Pure Tin Metal
Zinc Metal Powder.
Pure Sulphur; sublimed.
Pottassium Iodide.
Potassium Nitrate
Potassium Hydroxide.
(Caustic Potash)
Potassium Ferrocyanide.
Potassium Pyrosulphate.
Potassium Chlorate.
Tannic Acid Powder
Ammonium Carbonate
Pyrolusite (MnO)
Sodium Hydroxide.
(Caustic Soda)
Sodium Nitrate.
Sodium Sulfide.
Cobalt Nitrate
Lead Acetate
Salt of Phosphorous.
Silver Nitrate.
Dymethylglyoxime,
Cacothelin,
SOLUTIONS TO BE MADE AT HOME
1. MATERIALS: The following solutions are all made up at home by using Dry Chemicals or Powders as listed on previous page.
2. PURE WATER: In all cases where solutions are to be prepared with water we should use pure distilled water
SILVER NITRATE SOLUTION: To prepare.
1. Fill an ounce bottle about half full of pure distilled water.
2. Add silver nitrate crystals equal to 2 or 3 grains of rice.
3. Shake bottle to help dissolve. This keeps for a long time.
CACOTHELIN SOLUTION: To prepare - for Tin Test.
1. Fill one ounce bottle about 1/2 full of pure water.
2. Add Cacothelin powder equal to about 2 or 3 navy beans.
3. Shake bottle to help dissolve .
STABILITY: Keeps well; but as use only 1 drop per tin test 1/2 ounce lasts long time; so if stood over three months check stability before testing unknown ores. To check see Stannous Chloride below.
STANNOUS CHLORIDE: (Well Covered in Forum threads)
DIMETHYLGLYOXIME: To prepare solution (for nickel test ).
NOTE: Should be mixed with pure grain alcohol if possible: but we find acetone will do about as well.
1. Fill an ounce bottle about 1/2 full alcohol (or acetone).
2. Add dimethylglyoxime powder equal to 2 or 3 navy beans.
3. Shake bottle to help dissolve (all may not dissolve^ o.k.)
COBALT NITRATE : Dissolve crystals equal to about 2 or 3 navy beans in 1/2 ounce of pure water. This is seldom used.
SODIUM SULPHATE; Dissolve crystals equal to about 2 or 3 navy beans in 1/2 ounce of pure water. This is seldom used.
The following are seldom used, and then only a few drops per test, and as they do not keep well in water solutions. It is best to mix in a test tube as needed.
AMMONIUM CARBONATE: Dissolve powder equal to about 1/2 the size of navy bean in 2 or 3 cc of pure water; shake to help dissolve.
POTASSIUM FERROCYANIDE: Dissolve flakes or powder equal to about 1/2 navy bean in 2 or 3 cc. of pure water.
CHARCOAL FLUX: This is not a solution, but as it is to be prepared at home, will be given here. This is used in all tests in Part Two where fusions are made, unless otherwise stated. It will work on practically all minerals, and thus save making up a different flux for each elements.
TO PREPARE: Mix thoroughly 4 volumes of powdered borax; 4 volumes of sodium carbonate (anhydrated, not common baking soda), and two volumes of powdered charcoal.
BISMUTH FLUX: This is another powder mixture to prepare at home. It is used in the testing of bismuth, or to distinguish bismuth from lead, as given in Test 25, Part Three. As it is used mostly as a confirmatory test, best to mix up as needed.
TO PREPARE: Mix equal parts potassium iodide and sulphur.
GYPSUM TABLETS: While "Bismuth Flux" may be successfully used on charcoal, the colors, especially for low-grade lead or bismuth, will show up much plainer on white gypsum tablet. Can also test antimony or arsenic by first blackening the tablet by holding in smoky flame, such as with match or coal-oil lamp.
ADDITIONAL EQUIPMENT
1. BOX - for "Field Test Kit"; this should be about 7" high by 7" wide by 12" long.
2. TEST TUBE STAND
3. TEST TUBE HOLDER
4. GYPSUM TABLETS: For purpose: see previous page. One should make up a couple dozen of these and have handy.
TO MAKE: 1. Get 2 or 3 pounds of plaster of Paris. 2. Now take a common window glass or any flat glass; make a frame around the same about 1/4" higher than glass. 3. Now take amount of material you think will take to fill space. 4. Add plenty of water and mix quickly, make into thin sloppy paste, 5. Pour on glass, then immediately take a long knife blade or piece of tin which will reach to both frames, and level off smooth; 6. When thoroughly set,-remove from the frame, mark oil and with hacksaw cut into blocks about 1" by 2-1/2"
5. CROCKERY: Some fusions made with flux may sometimes be made on crockery (or flat piece of chinaware, such as broken plate), and thus save charcoal blocks. Have peices about 1" square or may be larger.
6. HOLDER: For holding gypsum tablets, Crockery or small pieces of charcoal for heating with blowpipe. A: Take a piece of fairly heavy galvanized iron 1" wide by 5" long; bend up one end about 1/4". B: Take a piece of tin can about 2" square; bend one end of this about 1/4" to match longer
piece; cut where necessary and bend around long piece, so will slide back and forth on the long piece to act as a clamp to hold pieces of crockery, etc.
THE BLOWPIPE: ITS PURPOSE AND OPERATION
NOTE: The operation of the blowpipe is the only thing in our complete instructions which requires any skill or practice. Practice by following the instructions given below, and well worth the time spent as we may identify more elements in less time than by any other method; and also important in other tests where fusions are required. See "Tests Made on Charcoal" in Part Two.
OBJECT OF BLOWPIPE: To change the normal vertical lamp flame into a horizontal direction controlled by the operator, and thus concentrate the heat of the lamp flame into a long slender cone which may be directed against the assay or object to be tested.
FLAMES: It will be noticed there are two cones to the flame; each has a different color, and each one used for a different purpose:
A: An outer yellow cone which is called the Oxidizing Flame.
B. An inner blue cone which is called the Reducing Flame.
NOTE: Place a cardboard behind lamp to better see flame colors.
THE OXIDIZING FLAME: Some substances when Oxidized produce certain reactions, which is the object of this flame. The best point for oxidizing purposes is within the yellow flame just outside the blue cone with the blowpipe.
THE REDUCING FLAME: Some substances when melted, fused or reduced to the metallic state, produce certain reactions. The object of this flame is to fuse Or melt the object being tested. The best point for this purpose is just within the tip of the blue cone. We will also find some materials must be melted or fused with some flux before they will become soluble in water or acids, as explained in Part Two.
OPERATING THE BLOWPIPE
One of the first and most important things to learn in operating is to blow a steady blast of air, and thus produce a steady flame. The following will give the general idea, and may be learned with just a little practice. NOTE: The blast of air is not produced by the lungs, but by air held in the mouth,
replenished by a gulping action as explained below.
1. Place the mouthpiece between the lips; lips closed,
2. Now place tip of blowpipe just within flame of lamp, to the right hand side and just above the wick.'
3. Now distend or blow up cheeks.
4. Breathe in through the nose - never through the blowpipe!
5. Exhale, slowly, through the blowpipe (little air is required) at same time breathe naturally through the nose.
6. When more air needed in cheeks, make a sort of gulping action with cheeks. (Do not suck air through the blowpipe.)
7. Keep cheeks distended at all times, only the fraction of a second necessary for the gulping action; the object is to try to blow as steady a stream of air as possible, with as little break as possible. Practice extending time between gulping actions. Practice on making actual fusions and bead tests.
QUICK QUALITATIVE ANALYSIS THIRD EDITION-REVISED
"METHOD OF PROCEDURE"
TEST No. 1: For vanadium, manganese, sulphides, carbonates.
1. Use amount of powdered mineral equal to 3 grains of rice.
2. Plate above in clean porcelain evaporating dish.
3. Add 3 or 4 drops of cold strong hydrochloric acid.
RESULTS
A: If a sulfide the odor of sulphur, resembling rotten eggs may be detected, (We catch sulphides again later on).
B. If a carbonate, powder will effervesce (bubble or 'fizz"), NOTE; Sulphides will also sometimes effervesce, but can be distinguished by the odor of sulphur as given above.
C. If vanadium is present both powder and acid will turn red or brown quicklv. If so confirm by Test No. 60.
D. If manganese (all black ores) solution will be a greenish-black. If so, confirm by Test No, 39, Part Three.
NOTE: If there is, or is not, a reaction above, use same dish and powdered mineral for next Test No. 2.
TEST No. 2: For molybdenum-lead or molybdenum-oxide,
1. Use same dish and powdered mineral from test No.l above.
2. Add 1 cc or slightly more strong hydrochloric acid.
3. Boil over lamp flame; while boiling watch for blue or green stain on dish; boil to dry if necessany.
4. Remove dish from flame and let set for a few minutes to cool.
RESULTS NO 1: Blue stain on dish , hot or cold , is positive test for Mo Pb ( Wulfenite) or MoC (Molybdate), A green stain in dish indicates one of the above may be present. If so, confirm by Test 41 Part Three which will prove yes or no,
RESULTS NO . 2: If no blue or green above test is complete as no Mo Pb or MoO present, so proceed' with Test 3 below. But if blue or green see 4 previous page to find if MoPb or MoO.
NOTE: If there is, or is not, a reaction above, use same dish and powdered mineral for next Test No. 3 below.
TEST No. 3: For, tellurium, or tungsten; and and all ores.
1. Use same dish and powdered mineral from Test No, 2 above.
2. Add 2 cc hydrochloric acid; boil slightly over lamp flame.
3. Remove from flame and while hot add small piece tinfoil.
RESULTS No. 1 for tellurium: If much tellurium is present solution will turn black; if but little Te. just a dark solution around tin. In either case confirm by Test 54„ NOTE: The above is dark solution- not coating on tin. Now continue test for tungsten, as follows
4. Place dish back over lamp flame and boil until solution changes colonthen a little longer. Do not boil to dry. RESULTS No. 2 for tungsten: A blue solution is a positive test for tungsten; color may not show up until cold, depends on grade of ore; solution may first be red, but will tarn blue
on standing. See Test 58 Part Three. NOTE: MoO or Mo Pb may also give a red color, but will not turn blue on standing.
TEST No. 4: For tin. Any ore or metal. Very positive test.
1. Place powdered mineral size 2 or 3 grains of rice in dish.
2. Add powdered zinc metal of about equal quantity.
3. Add 8 or 10 drops hydrochloric acid ( this is Test Solution)
4. Place 2 or 3 drops of above Test Solution in another dish.
5. Add 1 or 2 drips of cacothelin solution.
RESULTS: A pale to dark purple spot if tin is present; the darker the color the more tin. This is a very positive test, even for very small quantities of tin, and may be made semi-quantitative by making test on spot paper as given below.
NOTE: If no sign of purple color above, skip the following:
1, Place a piece of filter paper on clean piece of glass,
2, Place i drop of Test Solution above in center of paper.
3, Add i drop of cacothelin solution in center of paper.
TEST NO. 4 (contd.) For tin.
RESULTS: A small pale-purple spot if very low grade ore. A large pale-purple spot, or a small dark-purple spot if fair grade ore. If high grade ore the spot will be dark-purple and at least size of a dime. By using same amount of powdered mineral and comparing with a sample of known percentage, a fairly accurate percentage of the unknown may be estimated.
TEST NO. 5: NOTE: This is a "master test" by which we catch from one solution below the following 11 elements: sulphur, copper, nickel, lead, thallium, bismuth, cobalt, tellurium, molybdenumsulphide, arsenic, silver. ( in the order listed)
NOTE: Results Nos. 1-2 and 3 below are not intended as positive tests, but are given to show what they indicate if present.
TO PREPARE TEST SOLUTION
1. Place 2 cc of strong nitric acid in a clean test tube.
2. Add powdered mineral equal to about one large navy bean.
3. Boil about 3 minutes; a little longer rather than less.
4. Remove from flame and let set about 2 minutes or so.
RESULTS No. 1: A spungy mass rising to top of the solution shows sulphides are present. Confirm by Test No. 1.
RESULTS No. 2: Green solution indicates copper or nickel or both. Confirm nickel by Test 6; copper by test 14.
5. Now add 3 cc pure water free of chlorine (see page in Part Three). Heat slowly and carefully just to boiling.
RESULTS No.3: A rose-color indicates cobalt; See Test 8.
NOTE: We will call this test solution S for reference in making the following 9 tests from this one solution.
TEST NO.6; For Nickel (for any and all ores). Spot test.
1. Place a piece of filter paper on a piece of clean glass.
2. Place 1 drop dimethylglyoxime solution in center of paper.
3. Add I drop of Test Solution 5 above to center of damp spot.
4. Add 1 drop of strong ammonia to center of above spot.
RESULTS: A red or rose color, which will not fade, is a positive test for nickel. (Iron will sometimes give a red or rose, but will fade out within a few minutes). The brighter the color the more nickel present, (see Test 42, Part Three).
NOTE: The color, especially for low grade nickel, can usually be brought out plainer if wait until the paper is dry and then add another drop of strong ammonia to center of paper.
TEST NO. 7. Lead, thallium, bismuth, or bismuth and lead.
1. Place 2 drops of test solution 5 in an evaporating dish.
2. Add about 6 or 8 drops plain water to dilute solution.
3. Add few crystals potassium iodide (KI.); see FOOTNOTE.
RESULTS
A: For lead or thallium: If either present even in small quantities, there will be a yellow or brownish precipitate. Confirm lead by Test 25. Confirm thallium by Test II-J.
CAUTION: Do not mistake a yellow solution for precipitate; if a precipitate it will settle out in bottom of the dish, which may be plainer seen after has set for a few minutes.
B. For bismuth: If much bismuth solution will turn black.
NOTE: This is not a positive test for bismuth, but merely indicative, as too strong acid, or other impurities will sometimes cause solution to turn black with potassium iodide. But if there is a black color, and to be sure and not overlook bismuth, confirm by Test 25, Part Three.
C. For both lead and bismuth sometimes found in same ore. If much bismuth solution may first be black, but on setting for a few minutes black color will leave in which the yellow or brown precipitate of lead may easily be seen in dish. Confirm either lead or bismuth by Test 25, Part Three.
TEST NO. 8: for cobalt (any and all ores).
1. Place 10 drops test solution 5 in clean evaporating dish.
2. Boil over lamp flame until dry; just a little longer.
3. Remove from flame, while hot add 1 cc hydrochloric acid.
RESULTS: a green solution is a positive test for cobalt, any and all ores; but may confirm by Test No. 16.
NOTE: Use same dish and acid for next Test No. 9.
TEST NO. 9; For tellurium, molybdenum sulphide, arsenic.
1. Use same dish and acid from previous Test No. 8.
2. Place over lamp flame and boil off 1/2 solution.
3. Remove from flame and immediately drop in small piece of pure tinfoil while hot; tip dish and slowly rotate once.
RESULTS
A: For tellurium: If much Te. solution will turn black. If but little Te. a dark color around tin; Watch closely!
TEST NO. 9: (contd.) For tellurium, molybdenum sulphide, arsenic:
B. For molybdenum sulphide: Blue stain on dish is positive test for MoS, needs no confirming. There will also be a red or rose-colored solution after dish has set for some time.
C. For arsenic: A brown film or scales on dish or floating on solution indicates arsenic. Confirm by TestNo.ll-A.
TEST NO. 10: For silver, or lead, or both if together.
1. Now take tube with remaining test solution 5.
2. Warm slightly; filter into clean test tube, let cool.
3. When solution cold add 1 or 2 drops hydrochloric acid.
RESULTS: A white "curdy" precipitate or mass, or a milky-white or opal-color, all indicate silver or lead or both; color depends upon amount of either or both present.
NOTE: To determine if silver or lead or both, see pages Part Three, and proceed as given there.
TESTS MADE ON CHARCOAL
TEST FOR : As. Sb. Cd. Se. Os. Ge. S. Pb. Bi. Tl. Te. Sn. Zn. Al. Mg. Au. Ag. (Fe.Ni.Co.).
TEST NO. 11: CHARCOAL - NO FLUX. (Tests made with blowpipe).
1. Use powdered mineral equal to 2 or 3 grains of rice.
2. Place on end of charcoal block (stick).
3. Heat steadily and for some time in the Oxidizing Flame.
RESULTS: See, "Reactions to watch for" as listed below.
4. If no results in above, heat in the Reducing Flame
5. Now note if any reactions as listed below.
NOTE: For reactions of different elements see next page.
TEST NO. 12: CHARCOAL - WITH FLUX. (Tests made with blowpipe).
1. Use powdered mineral equal to 2 or 3 grains of rice.
2. - Mix with "Charcoal Flux" equal to a large navy bean.
3. Make into paste with drop of water; place on charcoal.
4. Fuse to liquid state with Reducing Flame, then, while hot, run knife blade under fusion, turn over then fuse some more; a good fusion is quite necessary.
RESULTS: The same as in Test 11, and as listed below; some minerals which show little or no reaction without flux, may show a good reaction with flux; so both should be tried.
NOTE: For reaction of different elements see next page.
REACTIONS TO WATCH FOR
(Both with and without flux)
A; SUBLIMATE: (Coating). If heavy or light; color; if near or distant from assay; color while hot color when cold.
B: VOLATILITY: If easy, fairly easy, or non-volatile; first in Oxidizing Flame; then try Reducing Flame,
C; FLAME COLORS: Note if any change given off by the assay itself; or sublimate if touched with the Reducing Flame.
D: Touch sublimate with R.F. (for instant only); note if a change in color, or colored flame; if so, what.
E: ODORS: Note if any; example: garlic-like odor indicates As. A radish-like odor indicates selenium, etc.
F: .SMOKE OR FUMES: Example: heavy white smoke indicates Sb. Fumes smart the eyes (good test) indicates Os. etc.
G: ASSAY: Note if any change in color or appearance; if so, what? Inspect hot; inspect cold.
H: FUSIBILITY: (No Flux): If easy, fairly easy, or hard to fuse, or infusible. Important in testing for aluminum or magnesium with cobalt nitrate; See Test 38 Part Three,
I: GLOBULES: Note if any small metallic beads; if so, their color, hot and cold.
J: SECTILITY: If globules are easy, fairly easy, or hard to cut with knife, (Such as Pb. Ag. Sn. Bi. e t c . ).
K: MALLEABILITY: If globules will flatten, or are brittle.
L: MAGNETISM: Test powder with magnet before heating; then after heating in R.F. Test mass after fusing with flux.
NOTE: AFTER FUSING WITH FLUX SAVE FUSION FOR TEST NO. 13.
REACTIONS ON CHARCOAL ( W i t h or Without Flux; try each ; see previous page)
NOTE: First 7 elements are positive; need no confirming.
A: White light coat, distant assay. Very volatile. Garlic-like odor. (Odor is most positive test) — As.
B: White heavy coat, near assay, bluish out-border. Volatile White smoke - continues after heating ' Sb.
C: Red or brown coat with bright blue border — - Cd.
D; Steel-gray coating, red outer-border. Volatile, If coat touched with R.F. an azure-blue flame; a peculiar radish-like odor; odor is positive test. - Se.
E: Sharp bromine-like odor; fumes smart the eyes Os.
F: First, pure white coat near assay, if more heat moves further out, assumes greenish to brownish or lemon color; if examined with lense coat presents a glazed or enamel-like surface. Small milk-white globules scattered on charcoal near the assay Ge.
G: A very sharp pungent suffocating odor --- D,
NOTE: Following are indicative; should be confirmed.
H: Yellow coating near assay; non-volatile. Small metallic beads on assay; malleable, easy cut •- — Pb.
I: Yellow coat near assay; non-volatile. May be small metallic beads on assay; harder to cut than lead Bi. (Confirm either lead or bismuth by test No. 25) '
J: A slight white coat and an INTENSE green flame Tl. (Confirm thallium by Test No.7)
K. Heavy white coat, blue out-border with yellowish cast, black band between; all burn off with bluish flame, which is also yielded by the assay itself Te. (Confirm tellarium by Test No.3; most positive)
L: Yellow hot, white cold coating; non-volatile, small metallic globules. If coating moistened with cobalt nitrate solution and assay strongly heated coating will - become bluish-green when cold
M: Yellow hot, white cold with blue border. Non-volatile. No metallic globules. If coating moistened as above and reheated, coat becomes a bright green - — Zn. {Confirm Zinc by Test 60, Part Three)
N: No flux; Infusible. If heated then assay moistened as in L. above and reheated, assay becomes green — - Al.
O: No flux; infusible. If heated then assay moistened as in L. above and reheated, assay becomes pink Mg. (Confirm magnesium by Test No. 38, Part Three)
P: With flux: red metallic looking mass or specks — - Cu. (Confirm copper by Test 14; most positive test)
Q: Yellow, soft, malleable globule, bead or button ---— Au. (Confirm Gold by Test 34, Part Three)
R: White malleable globule, beads or button - — Ag. (Confirm silver by Test 52, Part Three)
S: A magnetic residue after heating in R.F. and let cool indicates either iron, nickel, or cobalt present.
TEST 13-A: For Cb., Ti. - any ore. (Also W. Mo. V. Co.).
ALL these but Cb. and Ti. should have been found, if present, in previous tests, so main object here is to cover Cb. and Ti. However, reactions for others will also be given here to watch for. Some colors may occur quite soon, some only on standing until cold or longer -so watch both,
TO TEST: use same fusion from Test 12, or make a new one.
1. Pulverize fusion from. Test 12, or the new one.
2. Place in clean test tube with 2 cc hydrochloric acid.
3. Add a small piece of metallic tin (Tinfoil best).
4. Boil till solution changes color; then a little longer.
NOTE: Add more tin if solution does not change color,
RESULTS
A: Light-blue solution indicates columbium; may not show up until cold or longer. Color brighter if let set few minutes then add powdered zinc metal equal to 2 grains rice.
B. Dark-blue solution indicates tungsten. To determine if W. or Cb.: W. gives a blue solution in Test 3, Cb. will not.
C; A lavender solution indicates Tl. Confirm by Test 57.
TEST NO. 13-A: (contd.) For Cb., Ti. - any ore. (Also W.Mo.V.Co.).
D. A red or rose solution if Mo. present. Positive test.
E. A green solution indicates V. or Co. Confirm V. by tests 1-17 and 60. Confirm Co. by tests 5-8 and 17,
NOTE; In above, charcoal may remain in suspension and thus make colors hard to distinguish; if so, may proceed as in Test 13-B for Cb. and Ti. If no color above can skip 13-B.
TEST NO. 13-B: Special test for Cb. and Ti. If in doubt above.
1. Place a piece of chinaware in adjustable holder.
2. Place on same powdered borax {or borax glass best) equal to about 1/2 size of common pea (more or less).
3. Add powdered mineral equal to about 2 grains of rice.
4. Add sodium hydroxide (pellet best) equal 1/2 size pea.
5. Fuse well with blowpipe, while hot turn over with knife blade and fuse again. A good fusion is necessary.
6. While hot remove fusion and crush in porcelain mortar.
7. Place in test tube with 2 cc strong hydrochloric acid.
8. Add 1 or 2 small pieces of metallic tin (tinfoil best).
9. Boil until solution changes color; then a little longer.
RESULTS: Same as in Test I3-A, but colors plainer seen. Let set a few minutes then add zinc powder size 2 grains rice.
TEST NO. 14: For copper, any ore; most positive test for Cu.
1. Place small piece scrap charcoal in adjustable holder,
2. Place on same small piece mineral size of match head.
3. Heat to redness in oxidizing flame of blowpipe.
4. Add 1 drop hydrochloric acid; now reheat with blowpipe.
RESULTS: a blue or green flame if any copper present.
TEST NO. 15: For mercury (Hg). Method of procedure,
NOTE: Cinnabar is only main ore; it is very characteristic color (usually vermilion-red or scarlet; very few rocks even resemble it. Should have known sample cinnabar, then test for Hg. only when your rock resembles same, in which case see Test 40 Part Three, and proceed as given there.
BORAX AND SALT OF PHOSPHOROUS BEADS General Information
BORAX BEADS: Made on platinum wire, as follows:
1. Heat end of platinum wire in flame of the alcohol lamp.
2. While hot quickly touch to borax powder.
3. Reheat in lamp flame until fusion stops,
4. While hot touch again to borax, then reheat; repeat this until bead is about the size of a small grain of rice.
5. Now heat with blowpipe until bead clear and transparent,
6. While hot touch to few specks of roasted powdered mineral.
7. Heat for some time in the O.F. (Oxidizing Flame) of blowpipe. Note the color, if any, while hot and when cold.
8. Now heat in R.F. (Reducing Flame): note color, hot, cold.
9. If no color, add few more specks of mineral; try again.
Repeat this until bead is saturated (opaque)
RESULTS: If an appreciable amount of element is present a point will be reached where color v. ill show up as listed on following page. NOTE: In making or heating bead, hold wire horizontal to remove bead hold wire vertical, then heat.
SALT OF PHOSPHOROUS BEADS: These are made same as Borax beads, except salt of phosphorous is more liquid when hot, and thus harder to hold on the wire; beads must be built up slower, using less material at a time. In building up bead, hold higher above lamp flame, then gradually lower.
AMOUNT OF MINERAL TO USE: From a very few specks in most cases, up to the amount where the bead is saturated (opaque). This depends upon kind of mineral, quality and impurities. Generally speaking just a few specks are sufficient.
ROAST MINERALS FIRST: All minerals should first be roasted on charcoal before making bead tests, otherwise bead may be dark or brown.
TO ROAST: Place a little mineral on charcoal, heat to red in O.F. then in R.F. ;wind up by heating in the O.F. -CAUTION: Note results, if any, for following reasons:
RESULTS: If any smoke or coating on charcoal in roasting, continue to heat in O.F. then in R.F. until all smoke and sublimate cease; otherwise volatile minerals will alloy with the platinum; this will not "salt" the wire, or cause any color in future tests, but will make the wire brittle, and cause
it to break oil and thus waste the valuable wire.
CAUTION: A clean wire must always be used, or may "salt" the wire from a previous test, that is providing a color was obtained in a previous test; if no color in previous test then need not be as no danger of "salting".
TO TEST 'WIRE: Make a bead in usual way (without using any mineral). Heat in O.F. then in R.F.
RESULTS: If no color shows up the wire is ok; but if color then clean wire.
TO CLEAN WIRE: Boil in a little hydrochloric acid then wash well by shaking back and forth in clean water.
NOTE: For bead colors of the elements see following:
BEAD COLORS OF THE ELEMENTS
-With Borax and Salt of Phosphorous -
ABBREVIATIONS : Yel. means yellow; Cls. means colorless. O.F. is oxidizing flame.
R.F. is reducing flame (blowpipe).
NOTE: All these elements but U. and Di. were covered in previous tests; but colors given here will help to confirm.
TEST NO. 16: BORAX BEAD COLORS
CHROMIUM - Cr. O.F.: Yel. hot; green cold. R.F.: Green hot; green cold. Confirm by Test 27 as given in Part Three.
VANADIUM - V. O.F.: Yel. hot; green cold. R.F.: Green hot; green cold. Confirm by Test 60 (Any ore containing V. should also be assayed
for uranium as they many times occur in same ore).
URANIUM - U. O.F. : Yel. hot; Ylsh-green cold. " R.F.: Green hot; green cold. Confirm by Test 59, but above is always worthy of assay.
DIDYMIUM - Di.
NOTE: Is a mixture of neodymium(Nd) and. Praseodymium ( Pr.) O.F.: Rose Hot; rose cold. R.F.: Rose hot; rose cold,
We have no confirmatory test for Di; usually none needed.
COBALT - Co. O.F. Blue hot; blue cold. R.F. Blue hot: blue cold. This is a very positive test; but may confirm by Test 8.
IRON - Fe. O.F. Yel. hot; cls. cold. R.F.: Yel. hot; cls. cold. NOTE: May be pale-green cold; see Test 36 in Part Three.
TEST NO. 17: SALT OF PHOSPHOROUS BEADS
NOTE: Borax beads are best for practice, but salt of phosphorous covers more elements more accurate; so best to use. Confirm same as Borax above, unless otherwise stated below.
CHROMIUM - Cr. O.F.: Green hot; green cold. R.F.: Green hot; green cold.
VANADIUM - V. O.F.: Yel. hot; yel. cold. R.F. Green hot; green cold. NOTE; Yellow in O.F. when cold distinguishes V. from Cr.
URANIUM - U. O.F.: Yel. hot; yel-green cold. R.F. : Green hot; green cold.
MOLYBDENUM OXIDE - MoO. O.F.: Yel. hot; cls. cold. R.F.: Green hot; green cold. Confirm molybdenum oxide by test no. 2; most positive test.
COLUMBIUM – Cb O.F.: Yel. hot; Cls. cold. R.F. Brown hot; brown cold. Confirm by Test 13 -B; most positive test for columbium.
DIDYMIUM - Di. O.F.: Rose hot; rose cold. • R.F.: Rose hot; rose cold.
COBALT - Co. O.F. Blue hot; blue cold. R.F.: Blue hot; blue cold.
IRON - Fe. O.F.: Yel.hot; cls. cold. R.F. Yel.hot; cls. cold. Note: Iron with saturated bead may be pale-green cold.
SECOND PROCEDURE
TEST MADE ON CONCENTRATES
-General Information -
1. After completing our Qualitative Analysis on the crude ore, as given in previous pages, we then proceed to concentrate our rock in a gold pan, then re-check for the heavier elements, such as gold, silver, lead, bismuth, nickel, tin, tungsten, uranium, tantalum, columbium, platinum minerals,
etc., which due to their high value may be present in paying quantities, but did not catch in the first procedure on the crude ore due to small quantity material used in testing.
2. Note: If any sulphides or tellurium found in the first procedure, roast ore thoroughly before panning.
3. To Roast Ore: Place crushed or powdered ore in a metal container, such as an old frying-pan, pie tin or shovel, place over open flame, such as camp fire, stove with lid removed, or better in a blacksmith forge. Heat, and hold to a dull redness for 10 to 30 minutes, or until no more smoke or any sulphur fumes given off; keep stirring ore while roasting.
4. Another good method: For any and all rocks. Heat rock for some time, to red if possible, in camp fire, stove or in blacksmith forge; then stand back in case rock explodes and toss in bucket of cold water. This will help free rock of sulphides and tellurium, also reduce certain elements to the
metallic state, such as lead, bismuth, gold and silver tellurides, etc. Also make rock easier to pulverize later on.
5. To prepare ore for concentrating: Take a pound or more of your rock, crush in iron mortar or other means until all will pass through window screen, then place on a buckboard and with muller pulverize to flour fineness.
6. Buck-board: Any smooth flat piece of iron will do, such as old stove lid, but larger the iron, the quicker the work.
7. Muller: For rubbing or grinding ore on buck-board. Any piece of smooth flat iron will do; the bottom plate of an old discarded electric flat-iron is ideal for this purpose.
8. Panning: A 6 inch frying pan with handle cut off is a handy pan for lab. work. Fill an extra pan with water. Place powdered mineral in gold pan, fill with water, shake vigorously to settle heavy materials; now by lowering and raising pan in water, wash off lighter materials; stop and shake pan often; repeat this until only a spoonful or less remains.
9. Results: If any heavy concentrates in pan, especially if non-magnetic, as explained on this and following page, recheck for heavier elements as given in paragraph 1 above. Also check for gold and platinum minerals by tests 18 - 19 - 20 - 21.
GOLD AND THE PLATINUM GROUP MINERALS
- General Information -
1. Gold: The first thing to remember , and this will apply to old timers as well as greenhorns: While pure gold is always yellow it is seldom if ever found in the pure state in nature, but is always associated with other elements which may change its color; such as alloyed with silver or mercury, in which case it may have a bronzy white color; or in chemical combination with tellurium, in which it will look silver - white or gray; ir associated with iron oxides , in which it may be coated brown or red; or may be coated jet-black if found in manganese, and thus mistaken for black iron. So to make sure all concentrates should be checked for gold by chemical tests.
2. Platinum Minerals: There are 6 minerals known as the Platinum Group: Platinum , Palladium, Iridium, Osmium, Rhodium and Ruthenium, listed in the order of their frequency of occurence as well as uses. We seldom if ever find any one of these in the pure state in nature, but in practically all cases will find two or more alloyed together, and in some cases traces or more of all six. This greatly simplifies our work in their identification, in the following manner:
In practically every case each one will contain either Platinum or Palladium, or both. In Part Three we give tests for all 6 elements; while the tests for iridium, osmium, ruthenium, and rhodium are all fairly accurate on the pure elements, they are not always accurate as found in nature due to impurities; but the tests for Platinum and Palladium are always accurate in all cases, regardless of impurities , with the following results.
We first test for Platinum and Palladium only: If both of these are absent in our concentrates, and while there are possible exceptions, we can usually quite safely assume that none of the other 4 are present. If we find either Platinum or Palladium, or both, v\e then have our ore or concentrates assayed for Iridium and osmium as well as platinum and palladium. Rhodium and ruthenium usually occur in small quantities and are obtained as a by-product in the refining of other platinum minerals , and are seldom if ever paid for. The natural colors of platinum and palladium are silver-white or gray, but as found in nature, due to other impurities , they may tarnish black , resembling black iron, or may have a yellow or a bronzy cast resembling iron pyrites. For these reasons all heavy concentrates should always be tested for Pt. and Pd. regardless of color.
3. Characteristics : Gold , platinum and palladium are all quite soft and malleable ; may be cut with a knife and will flatten without breaking. Iridium is also somewhat malleable, but harder. The only other soft malleable elements occuring in nature are native silver, bismuth and copper, all of which can be easily eliminated as follows: Silver, copper, and bismuth are all soluble in nitric acid; gold and platinum are not soluble in any single acid, but are both soluble in Aqua Regia, so if your material dissolves in nitric acid you can be sure it is not gold or platinum. Palladium is somewhat soluble in nitric acid, giving a wine-red solution, and completely soluble in aqua regia , and thus, gold , platinum and palladium can all 3 be detected if present in any aqua regia solution by the four simple tests 18-19-20 and 21 as given on the following,
TESTS FOR GOLD - PLATINUM - PALLADIUM
TEST No. 18 : To prepare test solution for Au. Pt. Pd.
1. Pick out particles suspected of being Au. Pt. Pd. or use concentrates equal to about one navy bean or pea.
2. Place the above in a clean test tube.
3. Add 1 cc Nitric and 3 cc Hydrochloric Acid ( Aqua Regia)
4. Boil over lamp flame for at least 5 minutes or longer.
RESULTS : Gold, platinum or palladium, if present , are now in solution , from which we will make the following 3 tests.
NOTE: To become familiar with the various colors and other reactions in the following tests, one should first practice on known samples of gold, platinum and palladium,
TEST No. 19: For Gold - Au. Spot Test with stannous chloride.
1. Place a piece of filter paper on a clean piece of glass.
2. Place one drop of Test Solution 18 in center of paper.
3. Add one drop freshly prepared stannous chloride solution. ( To prepare solution see article 6, Part One).
RESULTS: If gold is present there will be a purple or rose colored spot when paper is dry; color depending on amount of gold present ; the darker the dolor the more Au. Color will show plainer , especially for low grade ores, if let paper dry then add another drop of stannous chloride solution.
TEST No. 20: For Platinum- Pt. with potassium iodide - K1 .
1. Place about 20 drops test solution 18 in evaporating dish.
2. Boil over lamp flame until dry; then just a little longer.
3. Let dish set few minutes to cool so will not break dish.
4. Add 3 or 4 cc plain water; reheat just to boiling.
5. Filter solution into another clean evaporating dish.
6. Add potassium iodide equal to about one grain of rice.
7. Warm solution slightly over lamp flame, watch, for color.
RESULTS: If Pt. is present the solution will turn a light or dark rose color, either at once or after set few minutes; the more Pt. present the quicker and darker the color. NOTE. Sulphides or other impurities may sometimes give a red color which may be mistaken for a rose, in which case proceed as follows: boil off say one-half solution to hasten evaporation, then let dish set until dry, then add few drops plain water. RESULTS: If Pt. a bright rose color; if sulphides or other impurities solution will be colorless. This is the most positive test for Pt. If solution appears red, add a few cc's plain water to better see rose color.
TEST No. 21: For Palladium - Pd. With Potassium Iodide. NOTE: If in above test for Pt., and upon adding KI and warming (lines 6 and 7), if Pd. present the solution will turn dark colored or black , depending upon Pd. present; the more Pd. the darker the color. There will also be a black precipitate in bottom of dish, which upon adding an excess of KI will disolve giving a wine-red color. However, the dark solution is the main test for Pd., otherwise a red color means nothing for reasons explained in test 20 for Pt.
PART THREE
INDIVIDUAL AND CONFIRMATORY TESTS
TEST NO. 22: Aluminum - Al.
NOTE: Mineral should be light colored, or become so on ignition: MUST BE INFUSIBLE: Test for fusibility first.
1. Place on charcoal piece size of 2 grains of rice.
2. Heat steadily on hottest part of the blowpipe flame.
3. Inspect with lens; note if fused even slightest on edge.
RESULTS: If any sign of fusion, test will not apply, as any fusion will turn blue with cobalt nitrate solution. If no sign of fusion, proceed with test:
4. Replace piece of mineral on charcoal.
5. Apply 1 drop of cobalt nitrate solution to assay.
6. Heat in hottest part of blowpipe flame; note results.
RESULTS: If assay turns blue indicates Al. but possibly zinc; check Zn. If no Zn. it proves presence of aluminum. If no blue by above test, proceed as follows:
7. Powder mineral: dampen with drop cobalt nitrate solution.
8. Heat in hottest part of blowpipe flame.
RESULTS: Same as results above.
TEST NO. 23: Antimony - Sb.
TEST A: Charcoal - No Flux (See Test 11).
1. Place on charcoal small piece about size 2 grains rice.
2. Heat steadily in the Oxidizing Flame of blowpipe.
RESULTS: Heavy white volatile sublimate near assay; white smoke; smoke may continue after heating ceased; smoke and sublimate is a positive test for antimony
TEST B: Charcoal - With Flux, (See Test 12).
1. Use powdered mineral equal to two grains of rice.
2. Mix with "Charcoal Flux" equal to two navy beans.
3. Heat and fuse in the Reducing Flame of the blowpipe.
RESULTS: Same as in Test A. (See Test 12 for reason why).
TEST No. 24: Arsenic - As.
TEST A: Charcoal - No Flux (Some arsenic minerals).
1. Use small piece of mineral size of 2 grains of rice.
2 . P l a c e on charcoal; heat in the Oxidizing Flame.
RESULTS: Light white sublimate, some distance from assay; very volatile; GARLIC-LIKE ODOR; positive test.
TEST B: Charcoal - With Flux (See Test 12).
1. Use powdered mineral equal to two grains of rice.
2. Mix with "Charcoal Flux" equal to large navy bean.
3. Dampen with water; place on charcoal block.
4. Heat and fuse in the Reducing Flame; note results.
RESULTS: Same as in Test A. (See Test 12 for reason why).
TEST NO. 25: Bismuth - Bi.
WITH BISMUTH FLUX: Equal parts potassium iodide and sulphur.
1. Place bismuth flux equal to about a large navy bean in a porcelain evaporating dish.
2. Add powdered mineral equal to about two grains of rice.
3. Dampen to thick paste with a drop of water and place on a charcoal block of gypsum tablet. (Gypsum tablet best for detecting small quantities of bismuth -easier to see).
4. Fuse thoroughly in the reducing flame of the blowpipe.
RESULTS: Yellow coating near assay, bright red border. This is most accurate test for even small quantities of Bi.
NOTE: This is also a good test for lead which gives a yellow coating near assay -no red border.
TEST NO. 26: Cadmium - Cd.
TEST: To detect 1% or less of cadmium even with much zinc. (Cadmium is found associated with some zinc ores)
1. Use powdered mineral equal to about two grains of rice.
2. Mix with sodium carbonate equal to about one navy bean.
3. Make into a thick paste with a drop of water.
4. Place on charcoal block and heat steadily in the reducing flame of the blowpipe.
RESULTS: Reddish-brown coating near the assay with a blue border; usually iridescent (Peacock) if only a little of the sublimate forms. Sometimes seen best when cold.
Note: Zinc being less volatile the white coating of Zn. forms only after continued heating. Check zinc by Test 61.
TEST NO. 27: Chromium - Cr.
TEST A: With salt of phosphorous bead.
Note: For making bead tests see instructions in Part Two.
1. Oxidizing Flame: Dirty-green hpt, emerald green when cold.
2. Reducing Flame: Dirty-green hot, emerald green when cold.
TEST B: Where iron, etc., interferes with the above test.
1. Place sodium carbonate, equal to one navy bean and same amount of potassium nitrate in an evaporating dish.
2. Add powdered mineral equal to about 2 grains of rice.
3. Mix above thoroughly and dampen with a drop of water.
4. Place on charcoal block and fuse thoroughly with blowpipe.
RESULTS: Fusion usually yellow if much chromium present.
5. Place 3 cc of water in a test tube and heat to boiling.
6. Add powdered fusion to water and reheat to boiling.
RESULTS: Chromium now in solution (usually yellow).
7. Filter solution into a clean test tube.
8. Add about 6 drops or so of glacial acetic acid.
9. Add a few small crystals of lead acetate. RESULTS: A yellow precipitate if much chromium present. To confirm: Shake tube and filter; let paper dry, then test precipitate with salt of phosphorous bead by Test A. above.
TEST NO. 28: Cobalt - Co.
TEST A: Made with either borax or salt of phosphorous beads.
1. Oxidizing Flame : Blue hot, blue cold.
2. Reducing Flame: Blue hot; blue cold.
TEST B: Quick test with nitric and hydrochloric acids.
1. Place about 1 cc nitric acid in an evaporating dish.
2. Add powdered mineral equal to about 2 grains of rice.
3. Boil to dry over lamp flame; remove and let dish cool.
4. Add about 1 cc hydrochloric acid; warm dish slightly.
RESULTS: A green solution if Co. Confirm by Test A above.
TEST No. 29: Columbium - Cb.
TEST: With borax fusion, hydrochloric acid and metallic tin.
1. Place borax powder size 2 navy beans in evaporating dish.
2. Add finely powdered mineral equal to about 2 grains rice.
3. Dampen with water, place on charcoal block, or chinaware.
4. Fuse thoroughly in the Reducing Flame of the blowpipe.
5. Turn over and fuse again. A good fusion is necessary.
6. Crush fusion and grind to powder in a porcelain mortar.
7. Place in test tube with 3 cc strong hydrochloric acid.
8. Add a small piece of pure metallic tin (Tinfoil best).
9. Boil until solution changes color; then a little longer. (Add extra tin if necessary to change color of solution).
RESULTS: A pale-blue solution if columbium is present. Color may not show up until solution is cold or longer. the colorlor may be brought out plainer if let dish set few minutes then add powdereded metallic zinc equal to about 2 grains rice.
NOTE: Tungsten will give a dark-blue solution in this test. To determine if Cb.. or W; Tungsten will give a blue color in Test 3, columbium will not, and thus their identification.
End Part 1
