White gold filled material

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Williamjf77

Well-known member
Joined
Oct 30, 2018
Messages
138
Hello everyone, been a while since I posted on here. I processed some gold filled material and one piece was white gold, I probably should have left it out but after my nitric step i incinerated the material then proceed to AR, it seemed to take a whole lot of nitric so I stopped adding and processed the pregnant solution like normal, got the gold. There was still solids ie foils left over so I processed all the solids that were left from first AR treatment. The pieces that were left over reacts with AR but takes forever to dissolve, the original batch was only 120g of mostly 1/10 1/20 12k.

I gave , up got a little gold from the second treatment but still have these foils that are now black pieces that fizz and look like they dissolve in AR but after probably 50ml of nitric in there for probably 1gram of gold I still have this mystery.

It’s not magnetic, it’s shape is too big to be springs or hooks or latches. I thought I just melted the foils and created pieces that were larger but now I’m thinking it’s some PGM metal, I do have a stain with stannous test that doesn’t look like gold.

Any thoughts?

Also there were no problems dropping gold like too much nitric.
 
It is possible that the white gold had a high percentage of silver so the silver is forming a chloride coat stopping the acid getting to the gold , try melting the material and go with just nitric to see if it will dissolve the other , presumably , silver leaving the gold .
 
My guess here is that is Platinum.
Can you do a hot AR boil with the white foils and then post a photo of a white spoon stannous test please?
 
Rhodium plating was often used to make white gold look more "white". It also protected the gold covering by making it harder.
 
Rhodium plating was often used to make white gold look more "white". It also protected the gold covering by making it harder.
Correct They sometimes plate white gold (& not just white gold filled) to make it whiter/brighter

They also sometimes Rh plate sterling silver jewelry to make it whiter/brighter &/or as well as to keep the silver from tarnishing

If its a foil(s) & doesn't dissolve in AR it is likely Rh plating

Kurt
 
They are really not using much Rhodium plating since the clean Diesel act happened look at the price.
This is why catalytic converters are being stolen off new truck dealers lots.

There used to be these $1 jewelry stores at the Malls in town here and all the silver items were plated in Palladium.
Back in the 90's Platinum was priced 30% higher than Gold and Palladium was priced just higher than Silver highest price ever.

For 30 years I lived next to a Gold buying shop and we tested lots of things to find what metals were plated on items.
I have even spoken with custom Jewelry shops that cast Rose Gold and add 2% Platinum to harden the product and made the red color brighter, not to even talk about the Green Gold formulas out there.

I have seen a lot of thing not dissolve in AR that should like the Platinum alloy used to make dental plates.
Boiling it in AR barley dissolves it, still have hunks of it stored that I gave up work on until a future time.

So we all are thinking a Platinum group metal in these foils.
We can agree on that.
I still would like to see a stain test result photo.
 
Silver looking foils that does not dissolve in hot AR will almost always be rhodium plating. Ever wonder why rhodium does not dissolve in AR? It is a strong catalyst metal. It breaks nitrogen/oxygen bond on a molecular level. It literally tears the nitric acid apart without effecting the metal. If any rhodium does dissolve in AR, it was not because of the nitric acid was oxidizing the metal. Rhodium is used as a catalyst for this reason. A catalyst is one component of a reaction that is unaffected by the reaction itself. It comes out just like it went in.
 
While this says silver my picture is from gold filled materials.
As stated above, not too long ago, rhodium was so cheap that it was plated over any other white metal because the luster can match many other metals. Also, it is more scratch resistant and needs less polishing. You can dissolve gold right out from under rhodium plating with AR.
 
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