Analysis of Gold Types

Hello again folks.

Thanks for all who answered my recent questions about gold melting/working, I am now set up and happily working with gold and silver.

I have a question about natural golds from around the world... as is well known gold occurs in many different geological ways and will often take into it's structure other minerals. So in some places you might find gold that is more yellow wheras in others a more richer orange colour, or white.

I have recently bought some natural panned river gold from Idaho in the USA and had fun melting down a small amount. It's colour was a very pleasant yellow, unlike the 24ct bullion gold I also melted. I was very pleased with it's workability and colour and made a nice pendant from it. Apparently the areas around Idaho were once covered with glaciers and all kinds of minerals could have been introduced to the gold when it was formed.

My question is: Does anyone know where I can find information on the internet about what minerals might be affecting the colour of this gold from Idaho? For example, if natural Tin was present then this would possible devalue the gold in this raw state? Or if it was something rare then it might add to it's value. Just wanted to know what was in this gold I am using.

I have a friend in Italy who can sometimes to those spectra-analysis tests but I am thinking the information is likely already out there?

anyone help me on this one? Thanks ;-) Heather

Reply to
Heather Coleman
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Here is one site - Any alloy of gold is less than pure gold - unless maybe Platinum (more than 2x value) if it can alloy with gold.

To the eye, gold can be valued more if pink or green in jewelry...

Use caution, often arsenic is a common mineral found with gold.

Be cautious in sending gold overseas - maybe a fleck is ok. That is all that is really needed for scientific testing. I caution due to possible Federal laws.


Reply to
Martin H. Eastburn

Idaho placer gold is found as native gold (pure), gold tellurides (gold has a strong affinity for tellurium), and direct gold-silver or gold-copper alloys. Tellurides may include copper, lead, antimony, or iron in addition to gold.

Go here

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a brief tutorial on the mineralogy of Idaho.


Reply to
Gary Coffman

Try an assay office. IIRC, there are lists and references available that can be referenced to identify the source of placer gold by it's composition.

Placer gold is never pure. The assay of the gold will tell it's composition. At least to the extent of how pure it is. Maybe down to the details of it's impurities.

That is my understanding, based on discussions with a friend of mine that has several large placer claims in the interior of British Columbia.

Cheers Trevor Jones

Reply to
Trevor Jones

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