The Crucible reference article from the Simple Wikipedia on 24-Jul-2004
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Crucible

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In chemistry, a crucible is a kind of laboratory apparatus that is usually a cup, made of porcelain or non-reactive metal, used to heat chemical compounds to very high temperatures. One of the earliest uses of platinum was as a material in crucibles. Metals such as nickel and zirconium are also used as crucible materials these days.

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