# Gold in these ores?



## kjavanb123 (Dec 6, 2016)

Hi,

I found the following mineralization index years ago upon hiking this area. 

Today had a visit and took samples to be smelted to find out if my suspicious comes true and if they contain any gold.

The dimention of this vein that was visible is approximately 5cm by 20 cm.



Here is another view of vein close to its host rock? 




I collected all the palacer types of rocks that seem like eroded from the vein for smelting, here is a photo of it,



I broke another ore and this is the crossed section of it,



Thanks for your comments.

Regards
Kj


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## kjavanb123 (Dec 6, 2016)

Here is a long shot of types of rocks around that mineralization if that helps recognizing what types of minerals are these.


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## kjavanb123 (Dec 6, 2016)

Few km west of these minerals I noticed these long veins that seem shattered,
















Again thanks in advance for all your comments.

Regards
Kj


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## Deano (Dec 6, 2016)

Unless you have struck an unlikely very high grade seam of gold ore you are unlikely to see any gold from smelting the ore.

There will not actually be enough gold present to see and the iron minerals present are notorious as interferents in smelting processes.

A better test method is as follows.

Take around 1 - 200 grams of the ore and put it in a pipe mill. This mill is just a piece of black steel pipe around 50mm diameter and 300mm long with an end cap screwed onto a thread on one end.

The sample is processed in several stages by putting a piece or two into the pipe and belting it with a length of 20 - 30 mm diameter steel rod until it has turned to fine pieces, think fine sand to bug dust.

Mix the products from the millings into a single pile and weigh out around 20 grams.

This 20 gram sample is placed into a 5 - 600 ml beaker with around 250 ml of full strength 4:1 aqua regia.

Add the ore slowly to the aqua regia to avoid any boil over caused from the ore components.

The beaker is heated on a hot plate so that the liquid simmers, not a rolling boil. Do this outside or in a fume cupboard.

During the simmering there will be orange brown nitrous oxide fumes evolved, take care not to breathe them.

After 20 to 30 minutes the colour of the fumes will change to white. Keep simmering for a further 5 minutes.

This ensures that all of the residual nitric fumes have been removed, the white is hydrochloric fumes.

Any gold in the ore has been dissolved and is in solution as gold chloride.

Take the beaker from the hot plate and let it stand to cool.

Usually the ore solids will form a layer on the bottom of the beaker with clear liquid above.

If you are unlucky and have an ore which will not settle then you will have to filter some of the liquid out.

You now do a standard stannous chloride test on a drop of the liquor to see if gold is present.

This test is the basis of a laboratory aqua regia assay for gold but just done in a very basic form.

A rough idea of the grade of gold, if any, is gotten from the intensity of the colour from the stannous test.

Deano


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## kjavanb123 (Aug 11, 2018)

Hi Deano

Thanks for this reply. I tried it with following sample ores that contained iron oxide.

Here are the sample photos for your reference;

Sample 1



Sample 2



Sample 3



Sample 4



Sample 5



More in next threat.


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## kjavanb123 (Aug 11, 2018)

Using my chain mill I pulverized samples, first I did sample 1 and sifted here is the photo of powder

Sample 1 pulverized and sifted. A 20-gram sample was taken as seen the following;



Prepared a 4:1 aqua regia 250 ml, and simmer it in this glass jar which was in a pot of hot water on a heater. 

Sample was added slowly, and heat continued for 30 minutes, nitric fumes appeared and after that the white fumes showed up, as you described. I let the solution sit for a while to cool to room temperature.

Here is the aqua regia solution of sample 1;



Here is a drop of solution, before adding a drop of stannous chloride solution,



Here is the result after testing it with stannous chloride test solution,



One question, if ore contains only silver, once dissolved in aqua regia it will settle as white powder, how can I distinguish it from the ore? One way I think is to leave it in the Sun, if silver chloride it will turn purple.

Thanks again for your help on this form of assay, I am processing the rest of samples and if I got any positive for gold I will post it here.

Best regards
KJ


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## nickvc (Aug 11, 2018)

Kevin if you suspect silver content test a sample using just nitric, filter or decant carefully and either try cementing with copper or add Hcl or salt.


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## kjavanb123 (Aug 11, 2018)

Nickvc

Thanks for the advise. I sure forgot about that basic test for silver.

Best regards
Kj


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## nickvc (Aug 11, 2018)

It will only work if you have metallic silver I suspect you may need to process the ore further to reduce it to metallics.


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## kjavanb123 (Aug 11, 2018)

Hi Nickvc

I think the AR will chemically process all the silver and form the silver chloride.

So far, out of 5 samples, 4 of them turned out negative on gold or silver. 

I will run the last one tommorow. This assaying method is really quick as to tell if any suspecting ore has any precious metals or not.

Again thanks for Deano contribution.

Best regards
KJ


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## kjavanb123 (Aug 12, 2018)

All

Finally, sample 5 seems to have had some gold as a drop of its AR with stannous chloride test solution changed color to very pale purple.

Here is the a drop of sample 5 AR solution,



After adding a drop of stannous chloride test solution,



Since sample 5 is mostly quartz, further testing can include a cyanide leach test on a 10-kg pulverized sample.

Thanks
KJ


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## kjavanb123 (Aug 13, 2018)

I am so hooked on this assay now. There are so many mineralized quartz ore around town, I just checked a sample taken from a massive quartz ore that have been worked in the past.

These giant quartz ore bodies were inside a military base which has been public for decades now.

Here is a shot of the quartz body which was exploited in the past, sample 6 was taken from the wall on the right. Lentgh goes for at least 1000 m over the top of the mountain, width is 3-5 meters.



Here is photo of sample 6 taken from different parts of the wall on the right.



After aqua regia test was completed, this is what solution looks like, notice there are two layers at the bottom, white color on top and brownish at the bottom.



A drop of aqua regia solution of sample 6,



Addition of stannous chloride testing solution,



There is a colorimetric method to determine the quantity of gold per ton of samples using aqua regia assay which I will try next.

Deano, again thanks a million for showing such a cool and super easy method of assaying.

Best regards
KJ


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