Springy things?

[MGH]

Has anyone seen these before? I got them from a local jeweler who got them from some other guy a while back. He doesn’t know what they’re from or how much gold they may contain. I’ve developed just enough of a relationship with him to ask for a small handful to examine on my own. Hopefully he’ll let me toll refine these or buy them outright if they’re worth processing. He has maybe two to three pounds of them.

I digested two of the pieces in some 50/50 nitric acid/DI water. There were some decent sized foils left as well as some tiny flecks swirling around. There’s also a white crystal left over which I’d have to figure out how to deal with.

Each piece is about two inches long and has some solder at one end. If you stretch them out, they’re basically a long rectangle plated on both sides. It would be 5½ by 7/64 inches, so: (5.5) x (0.109) x (2) = 1.2 square inches of plated surface per piece (only counting the plating on the two largest surfaces, not the super skinny sides). Ten pieces weighs 9.53 grams, so each is 0.953g.

Anybody know or have a good guess about the plating thickness, or even overall yield? I’m estimating 1.8 grams of gold per pound using the figures above and Samuel’s online calculator with a 10 microinch plating thickness.

Anyone know where they came from?

 

[rusty]

Why bother digesting everything when you could run those through a sulfuric cell.

Anything springy - chances are its Beryllium copper

 

[Geo]

or phosphor bronze.
http://en.wikipedia.org/wiki/Phosphor_bronze

possibly a slot connector that has a tab lock. it clicks in place and you have to press a tab to release it.

 

[MGH]

Thanks guys. Absolutely, sulfuric cell would be the way to go. That’s the first thing I mentioned to the jeweler when I saw the material. But I don’t have a cell set up, and I’m not sure I want to commit to it at the moment. Nitric I can do, and I get it relatively inexpensively.

But I’m not committed to anything at the moment. I just wanted to try to get an idea of the plating thickness. If it had come off all as powder, then I’d probably just pass on a toll refining. But I think this looks decent - except for the tin-containing phosphor bronze that Geo mentioned, which he’s probably right about. That’s certainly another reason to set up a sulfuric cell.

So, anyone have a good guess on the plating thickness?
Thanks.