Differential identification - Sterling or Nickel

I made one of those bonehead mistakes that many of you preach to be
careful about. I have some of my small pieces of sterling mixed in
with some nickel that I was using a couple years ago to learn on. Is
there anyway to tell which is which? Thanks for the help.

If you can do this (I have a specific gravity scale for doing gem
identification), specific gravity:

Ni = 8.9
Ag = 10.5

John

depending on howmuch nikkel you used in the alloy. Nikkel is
magnetic, silver not.

best regards
Pedro

How about deliberately tarnishing them? Get an aquarium and some
sulphur from the garden store. Place the items in the aquarium along
with a tablespoon of sulphur. Ignite the sulphur and cover the
aquarium. Leave it for an hour or so. Do this outside, the sulphur
dioxide fumes are toxic. The sterling will turn dark, the nickel will
not.

Paul Anderson

If it is nickel silver you can use acid to test. Get it at your
jewelry supplier. The copper in the nickel silver reacts and produces
a green colour - much more intense than the reaction to the copper in
sterling silver.

Karen

Hi, if we’re talking about the chemical element Ni = nickel, the
difference is easy:nickel is one of the ferromagnetic metals,
meaning it is magnetic or can be compelled by a magnet. The curie
temp. is 355 C., meaning that above this temp. it will loose its
magnetism. Unfortunately a lot of people are allergic to nickel.
Therefore if your silver is contaminated with nickel, its better not
to use it for jewelry, but e.g. flat ware instead. There are (fairly
cheap) tests for sale to determine nickel-contamination of your
material. separating the two metals while already being alloyed is
maybe hard to separate at home, I think. Unless you have the right
equipment for the proces… all the best,

Stephen Tjon
The Netherlands

Invest in a testing kit. Here in UK I’ve got a Troy Test. A tiny
drop of acid from the appropriate bottle turns an unmistakeable red
on silver.

Regards, Gary Wooding

I’m reasonably sure the OP means nickel silver or german silver and
not straight nickel. I believe the correct acid reactions are…
nickel silver bubbles green and sterling gives a gentler brownish
cream color. So if you’ve got a bunch of small bits and pieces simply
put a few layers of paper towels in an acid proof tray(your mother’s
pyrex lasagne dish maybe? yeah she’d like that) add some nitric acid
and spread the metal bits on it. You can see at a glance what’s what.
Do this outside.

Throw the dish away after a thorough rinse.

Or send the mixed batch for refining and just expect a lower yield.
Toss it in with your sweeps. If they’re that small its not worth a
separate assay anyway. You know…that bag you have to save til
retirement anyway.

There is a huge difference in hardness and toughness between the
two. Try scratching them with a piece of silver or one another. if
wire or sheet, try bending or pulling, the nickel will resist much
more and be much springier. Silver also has a much lower melting
point and will amalgam with mercury wheras nickel wont. Acid tests
will tell them apart as well, rub the metal on a piece of black slate
and put a drop of acid on the streak left behind. the silver will
whiten, the nickel [if leaving a streak] will remain untouched or go
green, depending on the acid.

There are lots of other thing you can try, thermal conductivity
[which gets hotter first when in contact with a heated objest.-it
will be the silver]. Indent tests [put them in a vice with a small
ball bearing between them and the one with the deepest indent will be
the silver. Again, you can standardise againt a piece of silver.

Hope that helps.
Nick Royall

For what it is worth, a fairly simple solution allows for a test to
distinguish between nickel silver and sterling.

30 ml distilled H2O
2 gm AgNO3
1 drop HNO3

Sterling to 90% silver content will yield a brown stain when a drop
is placed on the test object. As the silver content in tested samples
goes down the stain becomes darker. Nickel silver will instantly
stain black.

This solution seems to have a very long life stored in a small brown
glass bottle. The bottle I am using has a small plastic rod attached
to the inside of the lid for applying a droplet. All appropriate
precautions for dealing with chemicals would apply when mixing or
testing.

I made up this solution because I had the chemicals on hand and it
was late on a weekend when I needed to be sure about a suspicious
piece of metal. On the other hand, for under $5 one can find plenty
of sources for ready made testing solutions for this purpose on the
internet, an easier route to get a “yay or nay” answer to identify
silver.

J Collier
Metalsmith

Hello Peggy

if you have lot of quantity just melted and take it to an assying
company so he will tell you exactly how much pure silver you have if
you have countable pieces like 4 or 5 buy a kit and tested one by one
no other choice Pegg, and this is the site of the kit
http://www.ottofrei. com

Good luck
Ralph