Some thoughts on dealing with the "nightmare" form of second

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Spiritfire

Member
Joined
Dec 15, 2011
Messages
7
In mother nature sulfate minerals are derived from the oxidation of sulfide minerals. The case of precious metal bearing sulfide minerals oxidation processes produce precious metal bearing sulfates and some of these can yield large mineral deposits. Jarosite is an iron sulfate that can form blanket deposits carrying millions of tons of ore. If the jarosite contains precious metals this can form an impressive and high grade deposit. The most common of these is argentojarosite, or silver bearing jarosite derived from silver bearing pyrite. It forms yellowish to brownish crystals with a jarosite matrix. Gold bearing jarosite is also known. Recently a rhodium bearing jarosite was discovered in the Caballo Mountains of New Mexico.

But what about jarositic deposits in which the precious metals exist in really bizarre states? What about the jarosite derived from a gold, iron, telluride sulfide. O, even worse, a palladium, antimony, iron, bismuth, telluride in which sulfur is present.

Many of the precious metals have higher valency states that are never seen in the world of conventional chemistry, but can be seen in mother nature's chemical arena. Minerals such as the oxy-chloride of gold. Gold chloride does not exist in nature but the oxy-chloride of gold is abundant in nature. And it looks just like yellow limonite. There is also an oxy-chloride of silver and potentially other precious metals.

But what if you had an oxy-chloride of gold (or silver) combinated with ionic bonds to as many as nine other chemical structures? Is this not a nightmare? How would it respond chemically? My quess is that it wouldn't react with virtually anything.

Or would it?

One of my research projects has been seeking a means of converting some of the bizarre states of sulfate chemistry into easier to handle chemistry where the reduction of the precious metals can be carried out without it leading to heart attack and other deadly states of mind and body. And I have found something that works. It is also extremely simple chemistry and it can be purchased in most grocery stores.

The chemical is sodium carbonate.

Most of these unusual states of sulfate chemistry will react with sodium carbonate to form carbonates of the precious metals. While the carbonate minerals of base metals are fairly stable, those of precious metals are very unstable. As an example gold carbonate will seek to become metal by driving off the carbon dioxide as quickly as it can. Generally this only involves drying and powdered gold metal is left behind. Generally this is in an amorphous state and exists in microscopic particle size.

However, as long as the gold carbonate is wet it can be reduced by standard reagents and it is soluble in hydrochloric acid (with a lot of foaming).

When I am seeking to assayer a jarositic ore that can have a potentially difficult precious metal chemistry within it, I treat it was a solution of sodium carbonate, and then a solution of sodium sulfide. This reduces any precious metal carbonates to precious metal sulfides which can be assayed or even extracted with ease.

I hope this has provided something interesting to think about and perhaps it can help others overcome some technical difficulties.

Randy in Gunnison
 
I'm curious about this oxy-chloride of gold that looks like yellow limonite you mentioned. I have done some google searches on this but have failed to find any pictures of specimens. Can you provide any links to pictures? I'm just curious to see it.
 
Spiritfire said:
Many of the precious metals have higher valency states that are never seen in the world of conventional chemistry, but can be seen in mother nature's chemical arena. Minerals such as the oxy-chloride of gold. Gold chloride does not exist in nature but the oxy-chloride of gold is abundant in nature. And it looks just like yellow limonite. There is also an oxy-chloride of silver and potentially other precious metals.

But what if you had an oxy-chloride of gold (or silver) combinated with ionic bonds to as many as nine other chemical structures? Is this not a nightmare? How would it respond chemically? My quess is that it wouldn't react with virtually anything.

Or would it?

Randy in Gunnison
I'm very interested on this too, can anyone help shed some more light on it?
I've learnt to identify gold bearing material in the field in certain areas by looking for a type of mineral that superficially resembles Limonite but often contains little or no Iron.
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So far from my experiments I have thought from its reactions chemically that it is a form of natural Gold Hydroxide/Oxide complex and that the means of transport of Gold in its deposition is a natural form of Gold Chloride.
I have only found it in areas with saline groundwater, coastal areas and places that had been inundated at times of higher sea levels in history and it has always been associated with halide ores above sulfide veins or deposits and in adjacent enrichment zones

Cheers Wal
 
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