Anti-tarnish Chemical

This message is aimed at the cage of John Burgess, or any other
expert in chemistry.

Before I spend more money on anti-tarnish strips, or cloth, I would
like to know what the chemical is that absorbs the nasty sulfur. I
have a feeling that I may be paying for something which can be
purchased more cheaply from a local store than from a jewelry supply
house. Then again, if the anti-tarnish strips are made from exotic
chemicals, I’ll summon up a smile and send my money off.

Thanks in advance.

John McLaughlin Glendale, Arizona @John_McLaughlin

    This message is aimed at the cage of John Burgess, or any other
expert in chemistry. 

Who rang my cage bell? Strange as it may seem I would not class
myself as “an expert in chemistry” Because I know a little basic
chemistry and can apply it doesn’t make me an expert - “an expert is a
person with a briefcase 50 miles from home.”

   I would like to know what the chemical is that absorbs the nasty
sulfur. 

A substance called THIOUREA is well known as the foundation of many
of the tarnish removers available, like Goddards Silver Dip, and
Goddards ‘long life’ paste polishes. I suspect that the cloths do
contain that material, but I don’t KNOW. As for the strips purported
to inhibit tarnishing of silver, what they contain is a guarded
secret, but could again be our old friend thiourea, which is slightly
volatile at room temperatures, and thus when kept with the silver
could form a microscopic coating over the surface of the metal and
inhibit tarnishing by sulphur compounds. The most interesting thing
is that thiourea actually contains sulphur itself; hence the prefix
‘THIO’.

To sum up, I do know that thiourea dissolves silver sulphide and will
inhibit tarnishing when a very thin film remains on the surface. So
there you go and Cheers, – John Burgess; @John_Burgess2 of Mapua
Nelson NZ ----

Hi John Burgess, Roughly how quickly would the thiourea wear off if it
were applied to a ring… most off what i have seen as an antitarnish
is either a form of clear coat which lasts up to 6 months max. or a
plated process which is then not so nice when it wears off.

Daniel Grandi
http://www.racecarjewelry.com

I read somewhere (this list?) that the 3M strips contain activated
charcoal which absorbs the sulfur. They are certainly the right
colour! Karen

Most people are highly allergic to thiourea. NEVER leave it on
anything you clean. ALWAYS wash it off. It’s also poisonous! Children
die from swallowing the stuff!!!

Quote

Appearance: white. Warning! May cause allergic skin reaction. Toxic.
This substance has caused adverse reproductive and fetal effects in
animals. Harmful if swallowed. May cause eye and skin irritation.
Ingestion may result in an allergic reaction. May cause respiratory
and digestive tract irritation. May cause cancer based on animal
studies. Target Organs: Heart, liver.

See:-http://intranet.michener.on.ca/msds/tchem/thiourea.htm

Please be careful people!!!