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Test For Sterling Silver


#1

A lady came into my store the other day with an old teapot that
belonged to her grandmother. I don’t deal in antique silver, but I
wanted to at least tell her if it was solid sterling silver or not.
It “looked” like silver. There was a manufacturer’s name on the
bottom but nothing like “925” or “sterling”. Any suggestions? (I
use acids to test for gold). Thanks in advance.

Dale, in the Country Music State of Tennessee


#2
    A lady came into my store the other day with an old teapot
that belonged to her grandmother.  I don't deal in antique silver,
but I wanted to at least tell her if it was solid sterling silver
or not. It "looked" like silver.  There was a manufacturer's name
on the bottom but nothing like "925" or "sterling". 

G’day; Firstly I would suggest that if it isn’t stamped with the
usual marks is is most likely plated. The pot could be
electroplated, or if it is really an antique it could be what used to
be called ‘Sheffield plate’ This was made by rolling silver or
sterling onto a piece of base metal such as one of the brasses to
make a thin laminate, and is worth more than modern plate; rarity
value. Another base metal was EPNS; electroplated nickel silver.
(nickel silver contains no silver!)

A simple test for silver is to dissolve a tiny bit in a drop of warm
nitric acid. Add common salt solution to the result and if silver is
present you will get a white precipitate of silver chloride which
coagulates upon shaking and turns purple-ish in direct sunlight. If
you add ammonia dropwise to this the precipitate will re-dissolve,
then if you continue to add ammonia a pale blue colour will indicate
the presence of copper. So the metal could be sterling silver, or it
could be a brass, silver plated. Without very specialised equipment
it is difficult to give a scientifically based opinion on which it
is.

Cheers for now,
John Burgess; @John_Burgess2 of Mapua Nelson NZ


#3

Ask for permission and file a small cut into the surface of the
material. Apply a drop of concentrated nitric acid. Silver will
produce a white deposit, copper, brass etc. will give a green
deposit. The filing cuts through the silver/Sheffield plate (if any)
and tests the metal underneath

Tony Konrath.


#4

There is a Testing Solution that we use I comes premixed in a
bottle. You could buy this from Rio, Stuller or 46 Jewelry. The cost
is around 2 to 3 dollars. This is a test with Potassium Dichromate
and this turns the test piece into dark red. brown, etc., and this
helps you determine the purity of the silver. The color chart is on
the bottle itself. Get a fresh bottle as there is a shelf life on
this product.

Kenneth Singh