getting back to jewelry making

[cricketjo]

Hi there,

20 years ago I did jewelry making and really enjoyed it.  At the time, I bought some materials from an older woman who had decided not to make jewelry any longer.  The problem is, she told me that in the boxes of materials I purchased, sheet silver is mixed in with sheet nickel silver.  She did not remember which was which.  Recently my schedule has changed and I've been able to start making things again, but I don't want to misrepresent what I make/sell as real silver it it's not.  Can someone please let me know how I can tell which is which?

Thank you,
CricketJo

[Russ Nobbs]

They look different, they darken and tarnish differently, Nickel silver is stiffer. Nickel silver is an alloy of copper and nickel, a white brass.
If any of the pieces have green tarnish on them those are nickle silver.

The way a jeweler or coin shop tests silver is to put a drop of nitric acid on the item.
Nickel silver, brass or copper bubble up with a green foam as the Nitric reacts with the copper in the alloys.
Sterling does not bubble and when you rinse the acid off the silver has a creamy look where the acid was.

Nitric acid is NOT something you are likely to have hanging around the house.
It's a pretty harsh acid, but if  you can get some that's the easy way to differentiate the 2 metals.

[Russ Nobbs]

Another thought is to look carefully at the pieces and coils and see if you can segregate them into 2 piles.
Or maybe 3 piles: 2 that are clearly distinguishable as different from the other pile and a 3rd pile of stuff you can't see any difference in.

Then take a representative of the 2 main piles in to a coin shop or jewelery and ask them to test them to confirm that one pile is, indeed, silver and the other the copper alloy, nickel silver.

Some coin shops and rock shop/jewelry supply shops might sell small testing kits with a glass stoppered bottle (and maybe nitric acid)for testing and you can do this at home.
There are any number of chemical and lab-supply companies who sell nitric acid itself.

Doing your own testing may be the only sure way to tell what you have. The colors that the acid puts on the metals wil polish offwhen you make something form them and polish the product.

As I said, nitric acid IS hazardous.
Keep it away from children and pets.
Work with plenty of ventilation.
Work near a sink so you can rinse the acid off the product.
Don't get it on your fingers as it leaves a brown stain that tastes bad. (Can you tell that I've done this?)
Don't get it on your clothes. One of my staff learned how fast it eats through nylons!)
Have a box or large package of baking soda (not baking powder) handy to neutralize a spill.
Wash you hands thoroughly after testing metals.

Let me know if this information helps you.

[daverobertson]

@wendytgibson on Twitter wondered whether you can use a magnet to detect the nickel-silver.  I don't know how much nickel content there is in it, but I remember how the old Canadian nickels literally made of nickel were strongly attracted to magnets.

[cricketjo]

Hi Everyone,

And thanks for your feedback.  I tried the magnet -interestingly, it stuck to SOME of the nickel silver but I don't think all of it.  Could it be that some is older and formulated differently? 

Question about the colors of tarnish...  this stuff has been in boxes for at least 20 years (probably even longer before I purchased it), and there is very little tarnish on it.  The piece of nickel silver that was identified (and stuck to the magnet), still looks shiny new.  A few pieces of the other metal have some slight blackish spots on them but nothing with a distinguishable color.

I'll try to see if I can locate some nitric acid, but in the mean time, someone mentioned silver polish... they said if I try a bit of silver polish on silver, it'll turn the rag black, but if I use it on nickel silver, it won't turn the rag black.  Has anyone ever heard of or tried this method?

[Russ Nobbs]

Pure nickel (like the older Canadian nickels) is magnetic but none of the nickel silver findings or wire I checked was attracted to a magnet.
Iron, nickel and cobalt are all magnetic but nickel is the least magnetic of the 3. How magnetic a metal alloy is depends on the type of alloy. Some stainless steel (an iron alloy) is magnetic and other stainless steels are not magnetic.

I think it's possible that the piece that stuck to the magnet is actually iron or steel, not nickel silver at all, particularly if that sheet was very shiny.

Yes, silver polish or a silver polish cloth will turn black when rubbed on sterling silver. But brass and nickel silver will often turn a cloth black as it wipes off surface oxidation. Different silver polishes contain different chemicals so the results are not all the same.

Testing with nitric acid is still the most accurate method. A friendly coin shop might be willing to help you test a few pieces.