# What have I got here?!



## gladstone (Nov 26, 2012)

Hi there everyone, I have searched not just this forum but many others and the internet on the whole in an attempt to answer this question, all without success. I'm hoping an answer will be forthcoming here, after all - you are the perfect people to answer me. I thought I'd easily find the answer to what I assumed was a fairly simple question but no, so here we go.

I worked in London's jewellery/precious metals area for quite a while, in a shop buying and selling scrap gold and silver. Towards the end of my time there we, as a company, began to melt down the metal we had bought and turn it into bars. My question is this, after melting silver (and gold), are there any other metals that are produced? Often we would have lumps of blackened un-melted metal left over, we always saved it and re-melted it along with other "clean" scrap. I have a 400 gramme bunch of this metal and want to know if its silver/gold. In colour it is silver with bits of gold visible, its non magnetic, you can see what some of it was originally, like bits of chain and stuff. Basically I want to know if this is a mixture of silver and gold or if its just waste material from the melting process.

Thanks a lot.


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## tek4g63 (Nov 26, 2012)

I'd be willing to bet that you will find some answers here. This is the best precious metals site on the net.

Your answer will come easier if you ask something more like "How can I test this material for presence of gold/silver"

Also pictures help out a lot.

I wish that I could give you the answer your looking for, but I would just be guessing. Sounds promising to me though.

Welcome to the forum!


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## butcher (Nov 26, 2012)

Here is my thought on this. 

In jewelry there can be several other base metals and solders, my guess is these may have oxidized and this oxidized metal could hold some valueable metals like gold and silver.

I think there could be a couple of ways to deal with this material, like flux melting with a collector and pouring to a cone mold, or grinding and acid treatment, much would depend on what the metal or slag consistited of and what state it is in now.


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## g_axelsson (Nov 26, 2012)

To me it sounds like an incomplete melt. Karat gold and silver gets a black oxide on the surface when melted, it is the copper in the alloy that oxidizes into copper oxide which is black.
It could also be another base metal that is harder to melt than gold or silver.

Do you have any picture? It is easier to make a guess if we have something to look at.

/Göran


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## Geo (Nov 26, 2012)

silver jewelry is sometimes (actually most times) plated with Rhodium. silver melts at around 961 degrees C and gold melts at 1064 degrees C while Rhodium melts at 1964 degrees C. how much silver jewelry did you melt? does your furnace reach the melting point of Rhodium? if not, you could have a mass of unmelted Rhodium with gold and silver stuck to it.


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## kadriver (Nov 27, 2012)

I just melted some silver and gold alloy to inquart the gold before dissolving the base metals in nitric acid.

While doing the melt, I noticed some black metal that was not alloying very well, so I picked it out with some metal tweezers.

Then, while dissolving the base metals with nitric, I noticed a piece of black looking metal in the reaction vessel.

Using plastic tweezers, I removed this piece as well.

Thinking back, I had a pair of 14k cuff links in the batch and I failed to remove the steel springs from inside these cuff links.

Before inquarting, I try to remove all the steel springs inside the clasps - some earrings contain steel wire to serve as springs.

This caused my silver content to be over by a gram or so.

The result was much gold powder and colloidal gold instead of nice chucks of inquarted gold.

Cleaning the gold and silver mechanically by removing non-precious metals with hand tools and scraping off scum with a wire brush eliminates surprise junk from showing up unexpected.

Also, check EACH PIECE of metal before commiting it to the batch. If we rely solely on the stamp of the maker, then non-precious metals will certainly find their way in eventually.

kadriver


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