Some silver just isn't dissolving

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Rreyes097

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Mar 30, 2016
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661
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Northern California
Hello forum. I am currently dissolving some Sterling scrap jewelry in nitric acid and distilled water. The necklace dissolved the other bits of that I put in their dissolve but the ring which I thought was silver 925 isn't dissolving. It's a heavy man's ring and stamped 925 but doesn't look like much if any has dissolved after being heated and probably 20ml of nitric in total. The total weight of items was 25.6g. so I'm pretty sure that should be plenty to dissolve that little bit of silver. I took out the ring brushed it off with a toothbrush to get the top coating off and I clipped into it and seen no other color such as copper or I don't know any other color so it seemed to me like it was pure silver. But like a dummy I didn't bother to do a scratch test. Should I just do that now? What couldn't be the problem that it doesn't dissolve if it was indeed pure silver?
 
That's why I don't buy much jewelry. For less than $10.00, anyone can buy a 925 stamp, and stamp anything they want. I never rely on a stamp on jewelry.

Absolutely go ahead and test it now. You have nothing to lose. If it proves not to be silver, you can stop chasing what isn't there and save your chemicals.

There are plenty of white metals. In fact, most metals are white, other than gold and copper. There are a couple of others that aren't quite white, but most metals are white. Some, like nickel, are strong whiteners, so when added to inexpensive copper, the alloy is white. Consider the 5 cent coin. It's 75% copper and 25% nickel, and the alloy is very silvery.

Dave
 
It's just a solid band. Rounded to feel smoother on finger. No frills thrills just man's ring. And I used a neo magnet on all the items I put into solution and the only things that have any magnetism we're the springs in the clasps of the necklace. Which my magnetic stirrer thing managed to stick to and I was able to retrieve those. So I'm not sure what it's made of. I took it out earlier after several more ml. of nitric. Had a layer grey slimy stuff on it. Well not sure if it was slimy or not but I rinsed that off and the ring is still very much solid but cut in half and flattened out. I was hoping that cutting it would allow more area for acid to reach but nope. So I cleaned it off and will test it tomorrow with the silver test acid and a scratch stone. Unless y'all disagree?
 
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Okay thanks...

Not all stainless is magnetic, I just figured that was a quick check to you get you an answer quickly. Is there any other markings inside the band.

I assume your nitric is diluted with distilled water?..... water is important in this reaction.

If you have stannous chloride you can shave off some metal then add filings to AR. Once the the filings dissolve you can test for possible PM's, plus the color of the solution may help identify.
 
Don’t use a scratch stone to test silver. Use a small file and make a cut deep enough to get well below the surface. Then use Schwerter’s(spelling). If it turns red, it’s silver. If it turns green, it’s probably copper. And, as someone already mentioned, you need to be using distilled water to dilute the Nitric.
 
Okay thanks...

Not all stainless is magnetic, I just figured that was a quick check to you get you an answer quickly. Is there any other markings inside the band.

I assume your nitric is diluted with distilled water?..... water is important in this reaction.

If you have stannous chloride you can shave off some metal then add filings to AR. Once the the filings dissolve you can test for possible PM's, plus the color of the solution may help identify.
Thanks anyways 😉 your reply helped out a lot. Gave me some things to check into but sadly nothing came of it.
So yes I'm using distilled water as well. It's home made but it did the trick on the other things of silver I placed into the beaker with the ring. I'll shave off a piece tomorrow and try the AR. Because I took the ring out of the nitric and it is still very much intact.
As for makings, I don't know if you can see it in the terrible picture I put up but it has the outline of the 925 that made me think it that it was silver but maybe I didn't read it right? 🤔
 
Well looks like I have some information to report and I think I know what it means but I'm really not sure. Since there was no visible gold plating, am I to deduce that it is white gold?! 😋😁 Or could this just be a dirty glass that I didn't clean well enough after using it with AR and dropping gold? It took a few minutes for me to get even that purple reading. Let me back up.
So I did as suggested and I cut a sliver of what I thought was a925 sterling ring. But like the thread says it would dissolve with the other sterling. The other pic hopefully comes out well enough for you to see the silver. Any suggestions on where to go from here?
My thoughts are to go ahead and hit it with more AR? Or maybe not because it won't dissolve. Because of the silver and using nitric won't work because the karat count is too high. Am I correct? So what make shot out of it and add more silver to lower karat then try nitric? Or am I was off base?
 

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Well looks like I have some information to report and I think I know what it means but I'm really not sure. Since there was no visible gold plating, am I to deduce that it is white gold?! 😋😁 Or could this just be a dirty glass that I didn't clean well enough after using it with AR and dropping gold? It took a few minutes for me to get even that purple reading. Let me back up.
So I did as suggested and I cut a sliver of what I thought was a925 sterling ring. But like the thread says it would dissolve with the other sterling. The other pic hopefully comes out well enough for you to see the silver. Any suggestions on where to go from here?
My thoughts are to go ahead and hit it with more AR? Or maybe not because it won't dissolve. Because of the silver and using nitric won't work because the karat count is too high. Am I correct? So what make shot out of it and add more silver to lower karat then try nitric? Or am I was off base?
If you put it in Nitric and it is a Gold alloy which contain too much Silver, it might still dissolve enough to give Silver Chloride precipitation if you add Salt to it.

On the other hand it will probably test well on a XRF since it is plain metallic.
 
Well looks like I have some information to report and I think I know what it means but I'm really not sure. Since there was no visible gold plating, am I to deduce that it is white gold?! 😋😁 Or could this just be a dirty glass that I didn't clean well enough after using it with AR and dropping gold? It took a few minutes for me to get even that purple reading. Let me back up.
So I did as suggested and I cut a sliver of what I thought was a925 sterling ring. But like the thread says it would dissolve with the other sterling. The other pic hopefully comes out well enough for you to see the silver. Any suggestions on where to go from here?
My thoughts are to go ahead and hit it with more AR? Or maybe not because it won't dissolve. Because of the silver and using nitric won't work because the karat count is too high. Am I correct? So what make shot out of it and add more silver to lower karat then try nitric? Or am I was off base
If you put it in Nitric and it is a Gold alloy which contain too much Silver, it might still dissolve enough to give Silver Chloride precipitation if you add Salt to it.

On the other hand it will probably test well on a XRF since it is plain metallic.
Yes but to get it tested, well the only place I know is an hour away. I'm not sure who does it in my area. The place I know of is a simple pawn shop that probably wouldn't want to just test things for fun. So I'm hesitant to ask.
 
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