Patricia Reynolds ([log in to unmask]) said:

>Put _any metal_ next to gold and it will tarnish more quickly >than you
>would otherwise expect.  I used to know why, but I've >forgotten
>everything _Chemistry for Conservators_ told me.

This has to do with the 'Order of Reactivity' as some chemists call it - some
metals are more reactive then others, gold is one of the least reactive
metals, thus other metal stored near gold will react before the gold reacts.
 The same principle is used in galvanized metals, the metal that is used to
coat the base metal is considered a sacfically metal, it reacts leaving the
base metal protected by its by-products (usually an oxide).  This is not the
easiest thing to explain without showing examples, and its been a few years
since I had to teach chem (high school level only!) so it may not make much
sense.

Chrissie Devinney
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