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Latest Mohs scale of mineral hardness Stories

2014-02-03 20:20:18

SAN JOSE, Calif., Feb.


Latest Mohs scale of mineral hardness Reference Libraries

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2005-05-26 11:05:25

Corundum is the crystalline form of aluminium oxide and one of the rock-forming minerals. Corundum is naturally clear, but can have different colors when impurities are added. Transparent specimens are used as gems, called ruby if red, while all other colors are called sapphire. The word corundum comes from the Hindi kurand. The oxygen atoms in corundum are arranged in a hexagonal close-packing, with the smaller aluminium atoms occupying 2/3 of the octahedral gaps. The coordination of the...

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Word of the Day
dwale
  • The deadly nightshade, Atropa Belladonna, which possesses stupefying or poisonous properties.
  • A sleeping-potion; a soporific.
  • To mutter deliriously.
The word 'dwale' comes from an Old English word meaning 'error, doubt, delusion.'
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