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The Epic Interactive Encyclopedia 1998
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Epic Interactive Encyclopedia, The - 1998 Edition (1998)(Epic Marketing).iso
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G
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Gypsum
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INFOTEXT
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1992-09-03
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397b
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A common mineral, composed of hydrous calcium
sulphate, CaSO4.2H2O. It ranks 2 on the Mohs'
scale of hardness. Gypsum is used for making
casts and moulds, and for blackboard chalk. A
fine-grained gypsum, called alabaster, is
used for ornamental work. Burned gypsum is
known as plaster of Paris, because for a long
time it was obtained from the gypsum quarries
of the Montmartre district of Paris.