DarkspARCS said:
This has been an attempt to supply some form of support for the wonderful effort put into the creation of this forum. I'm hoping Richard 'the Rock Man' will come help make this post what it was designed to be, a location where folks can find identifiers for the ores they work with.
Thanks DarkspARCKS,
Below is a copy and paste of several of my more detailed posts covering essential
"Need to Know" information regarding prospecting for Hardrock, and Placer deposits.
I did my best to put them together in a way that flows together,
and fully conveys the thought, and info I was attempting to post.
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By reading the landscape it is possible to locate enriched areas of economic minerals.
These enriched areas are always in a zone that has gone through some grade of Hydrothermal alteration, Which is the process of magmatic gasses mixing with the water present within the melt to create acidic solutions that dissolve all metallic, and nonmetallic minerals at depth, and redeposit them close to the surface by precipitating out from solution as the pressure and temperature decreases. Oxides form toward the end of the cooling cycle, and sulfides form early while water is still present.
Minerals are scattered diversely throughout the crust of the Earth due to continental drift, and the resulting sea floor spreading, which in turn creates uplift and mountain building where oceanic plates collide with continental plates.
The subducted soil and rock with its metallic and non metallic elements are compressed, then melt due to extreme heat generated by compression. This mineral rich melt is a water rich melt from subducted sea floor material, which differentiates into magma plumes with various chemical formulas, and accessory minerals, which in turn are dissolved by the water reacting with the various gasses within the melt to produce acidic solutions that dissolve the metallic, and non metallic elements from within the melt.
This solution rises upward and deposits it's mineral load within the cracks, crevices, and spaces between mineral grains within the overlying rock strata as the pressure and temperature decrease, as well as in accordance with each minerals solubility, and solidification temperature. Sulfides below the water table, and oxides above the water table.
This process being what creates mineral deposits, for any area to have anything worth mining, it has to have a zone that has had some sort of volcanic activity. Not necessarily an explosive type as in MT. St. Hellens, or a passive type as those found in Hawaii, but some sort of magmatic upwelling below the crust had to take place to supply the heat, and gasses necessary for acidic solutions to have formed, and striped the melt of values, as well as the overlying rock, and redeposited its mineral load close to the surface.
What metallic and non metallic minerals are em-placed is just a matter of the luck of the draw. Rock types of any given region have a lot to do with what metallic, and non metallic minerals will be found.
There is such a thing as "Rock Type and Metal Associations".
I have listed a few in my various posts.
Such as Granitic rocks,
Granite, Monzonite, Diorite, Syenite, Granophyre, Tonalite, Carbonatite, and Skarn for Gold, Silver, Copper, Antimony, Bismuth, Tin, Lead, and Zinc.
Compressed and metamorphosed Basaltic sea floor for
Peridotite, Dunite, and Serpentine (Serpentinite) for Platinum.
Indicator minerals to look for will be those that have a melting point + or - 500F of the melting point of gold, if hunting gold, or of platinum, if you are hunting Pt.
With that being said,
Stream drainage patterns are directly related to the underlying rock of any given region, and reflect the type of geologic activity that took place there in the distant past.
I will focus on one.
That pattern is the "Dendritic Stream/River Drainage Pattern".
These river drainage patterns are associated with compression created by foliation in the mountain building process, as is the case with the Cascade and Rocky Mountain Ranges.
These ranges were created by Uplift, and Compression as the Continental Plate slid over the Oceanic Plate. This process generates great heat at depth which melts all material Subducted as it gets close to the Upper Mantle.
This Crustal Material is a wet material full of water.
This water is converted to steam, which then combines with the gasses within the melt to create various acids that dissolve all minerals within the melting Crustal Material, and the overlying rock as it makes its way to the surface, which redeposits its mineral load as it makes its way upward as stated earlier.
This Meteoric Water is also necessary for the magma to differentiate into the various Rock Types, Which are the Host Rock(S) for the various minerals, some of which are magmatic, forming within the melt itself, while others form from Hydrothermal solutions Created by the presence of water within the melt.
I will focus on those minerals created by Hydrothermal solutions.
These minerals are often associated with Granitic Rocks, and differentiation products thereof, because the intruding magma supplies the heat, and the water necessary for overlying enriched deposits to have formed.
These Granitic Rocks are often associated with Dendritic Stream Drainage Patterns, and therefore can be found simply by looking at a Topographic Map of the area that you intend to prospect.
Pick areas with a Dendritic Drainage Pattern, and you will be in the correct zone to find Economically Feasible Deposits of Metallic, and Non-metallic Minerals.
Dendritic Drainage Pattern areas are also the areas to prospect for Placer Deposits of Native Gold, and Platinum.
Not just Hard Rock Ores.
For simplicity, I will refer to Gold only,
but the same rules apply to prospecting for Placer Deposits of Platinum.
The ores containing Native Gold erode due to weathering, and as the encasing rock breaks down, it produces Elluvial Placer Deposits (Bench Placer). These deposits form on the slopes of hillsides where a depression or wide level spot occurs downslope of the eroding In Situ (In Place) Hard Rock Deposit from which the gold is eroding from.
Gold that works its way down slope to an area that is wide and flat produces an area known as an Alluvial Placer.
Dessert Areas are places where this type of deposit can be found, as well as areas that are predominantly Dry, whether hot or cold. They are most common in mild temperate areas with moderate rainfall that washes the gold down slope concentrating it in wide shallow depressions that fill with sediment washed into it by Runoff Water created by rainstorms.
The GoldFields of Ca. are a prime example of these two types of deposits.
From this point, whether or not Elluvial Deposits, and/or Alluvial Deposits form, if a Hard Rock source of Gold exists up-slope, the Gold is washed into Watersheds (Runoff Water Drainage Systems), where it forms Stream or River Placers.
The following is an explanation on how to work these deposits.
When working gravel bars,
Concentrate on those on the inside of a bend in a river.
Bends at an angle of 45 - 75 degrees are the most productive.
Of these types of bends, the ones flowing over bedrock, or over compacted clay, or clay and gravel Conglomerate are the best types of underlying ground for holding, and concentrating particles & nuggets of Gold, Silver, Platinum, and native Copper.
Look for Quartz, Agates, and other silicate minerals, as well as Tire weights, fishing sinkers, nails, wire, Buckshot, etc. mixed in with the black sand within these bends.
They are prime indicators that conditions are correct for precious metals to have been concentrated there.
Sluice, pan, or dredge from the surface down in these areas. If you wish to dig, then do so, but make sure that you work all gravel from about 14 inches above the "Hardpan" (Rock or Clay soil River or stream bottom).
Dig out Whirl Holes (Pot Holes) in the Bedrock Bottoms of Stream Beds.
Pan, Sluice, or Dredge the material out of these depressions.
This material will often contain fine gold, and nuggets, if Coarse Gold can be found in the region being prospected.
Cracks, and Crevices are a good place to look for Gold as well.
Dig, Break Open, Scratch or Scrape out the sediment from these, and pan it.
Cracks, and Crevices Parallel to the flow of water are the best to look in, as they seem to catch more Gold than Cracks, and Crevices that cross the flow of water.
I have never found any that cross the flow of water at an angle, but would like to. The down stream 1/3 of a crevice like that would contain concentrated values that fell into it, then agitated along the bottom of the Crack, or Crevice until it reached the down stream end, and lodged there.
RootWadds from Grass, and other Vegetation growing on Bedrock is also prime material to Break Apart, then Pan, Or Sluice.
Areas that widen out within a flow of water where the sand gravel, and rocks are dropped out, and concentrate, are good places to Pan, Sluice, or Dredge as well.
In these areas, keep a lookout for stretches of ground that have an abundance of tumbled somewhat round rocks above the current water flow. These areas are places where water once flowed, and are now exposed chunks of ancient river channel.
This material can be screened, then Panned, Sluiced, High-banked, or Dry-washed.
After you have panned, sluiced, high-banked or dry-washed your Pay-dirt,
You will be left with an abundance of Black Sand and mostly fine Gold, unless you are really lucky, (and some people are).
The best method that I know of for recovering your Gold from the Black Sand would be to put your sand into a Rock Tumbler, or a modified concrete mixer with steel balls and a small amount of mercury. Turn the unit on, and let it operate until all the sand has been crushed flour fine to recover all the visible fine gold, as well as any encapsulated gold bound up in solid solution with the black sand into the mercury.
Once the sand has been crushed flour fine, carefully pour off the water. The remaining sand can be ran through a "Blue Bowl", "Spiral Concentrator", such as a "Gold Wheel", or carefully panned in order to recover your mercury.
Place a piece of cotton, or filter paper inside a 500cc or larger syringe, then carefully pour your mercury into the syringe, then replace the plunger and depress it, forcing the free mercury out through the tip into a container.
The "Gold Amalgam" will be left inside the syringe against the cotton, or filter paper. Carefully Remove the cotton or filter paper with the gold, and place it into a Pyrex dish, and cover with a solution of one prt nitric acid, and 4 prts water.
Place the dish on a hot plate from an electric coffee maker, and let gently heat up.
The remaining mercury will go into solution, and the gold will remain.
Place a coffee filter in a plastic funnel, and then place the funnel into a glass dish in order to support it , and act as a resivior for the solution containing the mercury.
Pour the solution from the dish with the gold into the funnel, and let filter.
Rinse the dish with some extra water to make sure that all the gold has been removed from the dish, and is now into the filter.
Spritz the filter and gold with clean water to remove any remaining nitric solution containing mercury, and let drip, as well as sit until dry.
Once dry, The filter and gold can be melted with Borax to produce a single mass of gold.
Place a piece of copper plate into the nitric solution, and let sit overnight. The mercury will drop out of solution as free mercury within the solution, with some adhering to the copper plate, which can be scraped off, and the solution filtered to recover the rest.
There are 3 minerals that make up the bulk of all black sands.
Magnetite Fe Fe2 O4, Hematite Fe2 O3, and Ilmenite Fe Ti O3.
Magnetite & Hematite form during the magmatic stage as well as during hydrothermal, and metamorphic processes. Ilmenite forms during the magmatic stage, as well as during metamorphic processes.
Magnetite is associated with Andradite Garnet, Epidote, and Apatite.
It sometimes contains small amounts of Manganese, Nickel, Chromium, Titanium, Vanadium and Phosphorus.
It is a common constituent in many igneous rocks,
including Diorite, Gabbro, Monzonite, and Nepheline Syenite.
It occurs more specifically associated with Hedenbergite and Andradite in Hornfels;
With Almandine, Talc, and Andradite in Talc Schist;
With Calcite, Andradite, and Chlorite in Skarn;
and with Barite, & Fluorite in Hydrothermal Replacement Deposits.
Hematite occurs with Biotite, Albite, and Barite in Carbonatites;
with Diopside & Epidote in Hornfels;
With Quartz & Siderite in Mesothermal & Epithermal veins;
with Fluorite, Barite and Calcite in Lode and Disseminated Replacement Deposits.
Ilmenite occurs with Magnetite, Labradorite, and Hornblende in Gabbro.
Also occurs in Pegmatites, Nepheline Syenites, Gneiss, Chlorite Schist, and Diorite.
The reason that Gold is associated with these minerals is that they have mutual emplacement as minerals created by hydrothermal processes within fractures of overlying rock that has been intruded by magma, usually of Granitic composition.
Ground Water at great temperature and pressure mixes with Sulfur and Chlorine from the magma to produce solutions that dissolve all minerals, even Quartz, if Fluorine is present within the gasses that mix with the water.
As this super heated solution makes its way toward the surface through cracks, fractures, and spaces between the grains of overlying rock, the solution begins to cool, and pressure is relieved.
As this begins to happen, the dissolved minerals begin to drop out of solution by depositing on the cooler surface of the surrounding rock through which this solution is flowing.
Deposition takes place in accordance to each minerals solidifying temperature,
and solubility within the solution.
This is the process that produces Mesothermal, and Epithermal vein systems, which in turn are the same vein systems that we all strive to find when hunting Gold, Silver, and other economically valuable concentrations of metallic ores.
To put all this in a simple statement, the process that creates concentrations of Gold and Silver is the same process that creates the black sand minerals, and that is why they often contain Precious Metals. They formed together at the same time, from the same solution, in the same place.
The following is a list of Precious metal Ores, and their Chemical Formulas.
Acanthite ............................. Ag2S,
Calaverite ............................ AuTe2,
Sylvanite ............................. AuAgTe4,
Pyrargyrite ........................... Ag3SbS3,
Proustite ............................. Ag3AsS3,
Chlorargyrite (cerargyrite) ......... AgCl,
Polybasite ............................ (Ag,Cu)16Sb2S11,
Boleite ................................ Pb9Ag3Cu8Cl21(OH)16*H2O,
Moschellandsbergite ................. Ag2Hg3,
Allargentum .......................... Ag1-xSbx,
Dyserasite ............................ Ag3Sb,
Hessite ................................ Ag2Te,
Aguilarite ..............................Ag4SeS,
Argyrodite ............................. Ag8GeS6,
Stromeyerite .......................... AgCuS,
Jalpaite ................................ Ag3CuS2,
Freibergite ............................ (Ag,Cu,Fe)12(Sb,As)4S13,
Sternbergite ........................... Ag2FeS3,
Argentopyrite .......................... Ag2FeS3,
Miargyrite .............................. AgSbS2,
Nagyagite ............................... Pb5Au(Te,Sb)4S5-8,
Krennerite .............................. AuTe2,
Aurostibite ............................. AuSb2,
Xanthoconite ........................... Ag3AsS3,
Pyrostilpnite ............................ Ag3SbS3,
Samsonite .............................. Ag4MnSb2S6,
Pearceite ............................... Ag16As2S11,
Andorite ................................ PbAgSb3S6,
Stephanite .............................. Ag5SbS4,
Freieslebenite .......................... AgPbSbS3,
Diaphorite .............................. Pb2Ag3Sb3S3,
Iodargyrite ............................. AgI,
Sperrylite ............................... PtAs2,
Geversite ............................... Pt(Sb,Bi)2,
Insizwaite ............................... Pt(Bi,Sb)2,
Laurite .................................. RuS2,
Erlichmanite ........................... OsS2,
Gaotaiite ............................... Ir3Te8,
Mayingite .............................. IrBiTe
Here's a site where the above minerals can be looked at.
http://www.fabreminerals.com/fine-mineral-specimens.php
All high grade mineral specimens can be sold there.
The prices asked on specimens for sale by mineral collectors will shock you.
Metallic Ores produce various Colors as they oxidize,
and therefore stain the Host Rock(s) that contain them.
These stains are called Gossans.
The following is a list of the various Gossan Colors.
Yellows, Browns, Maroons, and Reds = ... Various Iron Oxides.
Black = ........................................ Manganese Oxides.
Green = ....................................... Nickel
Greens and Blues = ........................... Copper Sulfides, Oxides, Carbonates, Etc.
Bright Yellow = ................................ Molybdenum
Waxy Green = ................................. Native Silver, or Silver Chloride.
Oranges and Yellows = ....................... Arsenic
Pinks and Purples = ........................... Cobalt
The following is a list of Rock Types, and Metal Associations.
Granite = ........................... Gold and Silver.
Olivine Gabbro = ................... Platinum, Chromium, Nickel, Cobalt and Iron.
Dunite = ............................. Platinum and Chromium.
Peridotite/Peridotite Dunite = ... Nickel, Chromite, and Platinum.
Serpentinite = ...................... Platinum
The Following is a list of Gemstone, and Rock Type Associations.
Almandine = ......... Diorite, Hornfels, and Schist.
Andradite = .......... Granite Pegmatites, Carbonates, Hornfels, and Skarn.
Grossular = .......... Skarn, Marble, and Hornfels
Pyrope = .............. Peridote Dunite, and Gabbro.
Spessartine = ........ Granite Pegmatites, and Blue Schist.
Uvarovite = .......... Serpentinite, and Peridote Dunite.
Corundum = .......... Syenite, Nepheline Syenite Pegmatite, Hornfels, and Gneiss.
Beryl = ................ Granite Pegmatites, and Schist.
Tourmaline = ......... Granite Pegmatites, and Schist.
Spinel = ............... Hornfels, Marble, and Gabbro.
Topaz = ............... Granite pegmatites.
Zircon = ............... Granite Pegmatites, Diorite, Nepheline Syenite, and Carbonatite.
The following reactions take place with high grade ore.
Aqua regia (Neutralized) + Stanous Chloride = Purple to Black for Au. [Relevant to gold content]
--------------------------------------------------- = Yellow for Pt.
--------------------------------------------------- = Blue-Green for Pd.
---------------------------- + Potassium Iodide = Red Solution for Pt.
---------------------------- + Potassium Iodide = Black Solution for Pd.
---------------------------- + Acetone or Ethanol = Black precipitate for Rh.
Nitric acid + Hydrochloric Acid = A white precipitate of Silver Chloride.
Hydrochloric Acid = Orange Solution, + Nitric Acid = Black Precipitate for Ru.
(Precipitate redissolves quickly unless the HCL has been neutralized.)
Here is a listing of the books that I have in my library.
Recovery and Refining of Precious Metals.
By C.W. Ammen
ISBN 0-412-72060-4
Deep Rock Resources Inc.
P.O. Box 3258
Edmonton, Alberta, Canada, T5L 4J1 http://www.deeprock.ca
How To Smelt Your Gold & Silver
By Hank Chapman Jr.
Mineral Recovery Services, Inc.
P.O. Box 400
Wells, NV. 89835
Here are some books I suggest that you, and others get to study with, as well as look up and read in concerning anything that I have posted about "Minerals and Geology".
National Audubon Society
Field Guide to North American Rocks and Minerals. To order by phone, (800) - 733 - 3000
ISBN 0-394-50269-8
Simon & Schuster's guide to
Rocks and Minerals http://www.SimonSays.com
ISBN 0-671-24417-5
Dorling Kindersley Handbooks
Rocks and minerals http://www.dk.com
ISBN 1-56458-061-x
REBO PRODUCTIONS
Minerals Encyclopaedia http://www.rebo-publishers.com
[email protected]
ISBN 184 0134 046
ISBN 1-84053-163-0
David & Charles
Minerals & Gemstones of the World
ISBN 0-7153-0197-7
I hope that these books help.
Here are a couple of books that I recommend for those wishing to process "Black Sands".
Good information, and well worth reading for those who intend to do this.
Simplified Black Sand Recovery
By Clark Sable
Hulette Mining Company
P.O. Box 364
Reseda, CA. 91337
How to Process your Black Sand Concentrates
By Vern H. Ballantyne
ISBN 1-877700-07-X
Mountain Publications
P.O. Box 8008, Suite 252
Gloucester, MA. 01931
I hope that these books help, and they should.
I have used the methods described within them.
For those wishing to get a full understanding of "Structural Geology" of the landscape of any given region, I recommend the following books.
The Field Guide To Geology
By David Lambert and The Diagram Group
ISBN 0-8160-3823-6
Checkmark Books
An imprint of Facts On File, Inc.
132 West 31st Street
New York, NY. 10001 http://www.factsonfile.com
Discover Nature in the Rocks
By Rebeca Lawton, Diana Lawton, and Susan Panttaja
ISBN 0-8117-2720-3
STACKPOLE BOOKS
5067 Ritter Road
Mechanicsburg, PA. 17055
WINDOWS INTO THE EARTH
The Geologic Story of Yellowstone and Grand Teton National Parks
By Robert B. Smith and Lee J. Siegel
ISBN 0-19-510597-4
Oxford University Press, Inc.
198 Madison Avenue, New York, NY. 10016 http://www.oup.com
INTERPRETING THE LANDSCAPE
Recent and Ongoing Geology of Grand Teton & Yellowstone National Parks
By John M. Good and Kenneth L. Pierce
ISBN 0-931895-45-6
Grand Teton Natural Histroy Association in cooperation with The National Park Service
The Quaternary and Pliocene Yellowstone Plateau Volcanic Field of Wyoming, Idao, and Montana
U.S. Geological Survey Professional Paper 729-G
By Robert L. Christiansen
ISBN 0-607-95346-2
USGS Information Services
P.O. Box 25286
Denver, CO. 80225 http://geopubs.wr.usgs.gov/prof-paper/pp1623/
1-888-ASK-USGS http://www.usgs.gov/
Roadside Geology of the Yellowstone Country
By William J. Fritz
ISBN 0-87842-170-X
Mountain Press Publishing Co.
P.O. Box 2399
Missoula, MT. 59806 .... Phone # 406-728-1900 ...1-800-234-5308 http://www.mountain-press.com
[email protected]
The following are various other books within my library that I figured might be of interest.
Gold Diggers Atlas
By Robert Neil Johnson
Cy Johnson & Son
Box 288 - 435 N. Roop Street
Susanville, CA. 96130
GOLD! GOLD!
By Joseph F. Petralia
ISBN 0-88839-118-8
Hancock House Publishers
1431 Harrison Avenue, Box X-1
Blaine, WA. 98231 ... Phone # (206) - 354 - 6953
Sam Radding's Book of Plans -volumes 1 & 2
By Sam Radding
Sam Radding / Butterknife Publishing
6104 Adams Ave.
San Diego, CA. 92115 ... Phone # (619) - 582 - 0722
Western Gem Hunters Atlas
By H. Cyril Johson
Cy Johnson & Son
Box 288 - 435 N. Roop Street
Susanville, CA. 96130
N.W. Gem Fields and Ghost Town Atlas
By Robert Neil Johnson
Cy Johnson & Son
Box 288 - 435 N. Roop Street
Susanville, CA. 96130
Gem Trails of Oregon
By James R. Mitchell
ISBN 0-935182-99-3
Gem Guides Book Company
315 Cloverleaf Drive, Suite F
Baldwin Park, CA. 91706
Hoffmans Rockhound Guide
By Charles Hoffman
ISBN 0-936738-00-6
WEBB RESEARCH GROUP PUBLISHERS
P.O. Box 314
Medford, OR. 97501 ... http://sharplink.com/pnwbnooks
Standard Catalog of Gem Values
By Anna M. Miller & John Sinkankas
ISBN 0-945005-16-4
Geoscience Press, Inc.
Tucson, AZ.
The Nature Companions Rocks, Fossils, and Dinosaurs
Rocks and Fossils section by Arthur B. Busbey 3rd, Robert R. Coenraads, David Roots, Paul Willis
Dinosaurs section By Christopher A. Brochu, John Long, Colin McHenry, John D. Scanlon, Paul Wills
ISBN 1 877019 02-X
Fog City Press
814 Montgomery Street
San Francisco, CA. 94133
I hope that these books, as well as the above post helps everyone to find something interesting, and valuable.
Sincerely; Rick. "The Rock Man".
