[Jewelry making - Article 00745] - Re: [Orchid] Yellow tarnish on Silver

[John Burgess]

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>        I'm having a problem with this yellow tarnish that appears on
>     newly completed pieces.  I mostly work with turquoise and silver. 


    G'day;   Yellow or brown tarnish on silver is almost invariably due
    to the presence of a tiny amount of hydrogen sulphide in the
    immediate environment. I suggest that the black marks and tracery in
    some turquoise are copper sulphide and could therefore combine with
    atmospheric moisture to produce traces of hydrogen sulphide gas,
    which in turn, would produce a very fine film of silver sulphide on
    the silver surface. Your best trick will be to experiment to discover
    where the sulphur is coming from; either the turquoise or the bag.
    Perhaps a small piece of freshly 'burnt' lime (not limestone or
    chalk)  would help absorb the trace of sulphide gas in preference to
    the silver. -- Cheers for now, John Burgess;   johnb AT ts.co.nz of
    Mapua, Nelson NZ 



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