Alabaster - (Materials)

TheAntiqueTrade.co.uk Glossary of Antique Terms

Alabaster - (Materials) Alabaster is a name applied to varieties of two distinct minerals: gypsum (a hydrous sulfate of calcium) which is the type found now and calcite (a carbonate of calcium) which is the alabaster of acient times. The two kinds are distinguished from one another readily, because of differences in their hardness. The gypsum kind is so soft it can be scratched with a fingernail, while the calcite kind is too hard to be scratched in this way, although you can scratch it with a knife. Alabaster is usually white however it does come in colors, with black being the rareist with only three known veins in the world, China, Italy and Oklahoma (USA).

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