I have this ring stamped 10kt. It looks to be white gold. I melted it into a button because I was planning on mixing it with silver to lower karat to 6kt in order to refine it better. But I never got around to it. And while I was dissolving some silver I threw the gold button into one or 2 of these silver processes in order to use up any access nitric acid. So I did that and it helped. I think the nitric was able to dissolve any silver it could find in the button. And now it's actually gold in color. Now the gold is in my understanding purer. But I'm not sure how pure. Does anyone know if I need to still need to lower karat by mixing with silver? Or could I possibly get away with simply dissolving it into aqua regia? I've done this process in the past and was able to successfully lower karat with silver. Then made it into shot and then of course nitric acid to dissolve silver. But that was with a lot more gold and of varying karat. But since it's only a gram or two of 10k gold can I get away with aqua regia to dissolve it all?
10kt white gold ring
- Thread starter Rreyes097
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Martijn
Well-known member
The gold on the surface is purer, yes. That's why it looks better. But there is a good chance the acid can't reach the deeper layers, leaving the silver inside untouched.
You'll still need to inquart and treat with nitric.
AR will create a silver chloride crust that the acid can't penetrate to dissolve more silver. You could knock it off every now and then, but I would avoid creating silver chloride.
Check your dissolved silver nitrate for Palladium with stannous. White gold can contain Pd or be plated with Rhodium.
Other white metals can also be alloyed in to get white gold.
Martijn.
You'll still need to inquart and treat with nitric.
AR will create a silver chloride crust that the acid can't penetrate to dissolve more silver. You could knock it off every now and then, but I would avoid creating silver chloride.
Check your dissolved silver nitrate for Palladium with stannous. White gold can contain Pd or be plated with Rhodium.
Other white metals can also be alloyed in to get white gold.
Martijn.
Martijn
Well-known member
You could dry and weigh the button. If there is more than 10/24= 41.66% of the original weight left, there is more than just gold there.
I've never tested for palladium or rhodium. How is that done? And thanks for the information. So I guess no shortcuts this time I still have to lower the carrot count with some silver. Oh well
That's where I messed up martin. I never measured it when I first melted it I don't know why I didn't but I didn't gross mistake. But other than that it does weigh 1.3 g now!
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Martijn
Well-known member
Look for stannous chloride test on the forum. You can make it yourself by filling a clean eyedropper bottle halfway with HCL and put a small piece of tin in it. The tin will dissolve a bit. I keep the piece of tin in to keep it fresh and shake it up inside. Made it four years ago and it still works.
Put a drop of your solution you want to test on a piece of white filter paper or in a white spot plate. Add a drop af stannous and look for a reaction.
Purple to dark black is gold. Copper is brown.
Platinum group metals give different reactions, green for Pd i believe. Look it up. I'm not sure which is which.
Never had a pgm positive test as far as i know.
Your solution has to be free of nitric to test.
Put a drop of your solution you want to test on a piece of white filter paper or in a white spot plate. Add a drop af stannous and look for a reaction.
Purple to dark black is gold. Copper is brown.
Platinum group metals give different reactions, green for Pd i believe. Look it up. I'm not sure which is which.
Never had a pgm positive test as far as i know.
Your solution has to be free of nitric to test.
Oh I thought that the stanis chloride test was only for gold and that testing other precious metals required a different mixture of sorts. Thanks!
I'm laughing. Because when I said I didn't know about the stanis chloride testing you probably thought I really didn't know anything at all! My bad I was not clear.
Martijn
Well-known member
No worries. Here to help. I have to remind myself your membership time does not reflect active refining and studying time as you've explained.
Be very carefull with pgm's in solution. Very toxic stuff. And goes through the skin easily. Like most salts are a hazardous substance, pgm's are even more dangerous.
That's why i pointed it out.
Be very carefull with pgm's in solution. Very toxic stuff. And goes through the skin easily. Like most salts are a hazardous substance, pgm's are even more dangerous.
That's why i pointed it out.
You could flatten the button, as thin as possible, to expose more surface area for the nitric to attack which will save remelting.
I did indeed flatten the melted button that used to be a ring and it not flattened but broke apart. So much so that I was able to put in directly to aqua regia and I now have pure gold. 1.3g
