Hashemite is a very rare barium chromate mineral[1] with the formula Ba(Cr,S)O4.[2] It is a representative of natural chromates - a relatively small and rare group of minerals. Hashemite is the barium-analogue of tarapacáite. It is also the chromium-analogue of baryte, and belongs to the baryte group of minerals. Hashemite is stoichiometrically similar to crocoite and chromatite.[1] Hashemite is orthorhombic, with space group Pnma. I was found together with chromium-bearing ettringite and an apatite group mineral in the Hatrurim Formation,[2] known for the occurrence of rocks formed due to natural pyrometamorphism.[1] Hashemite is named after the Hashemite Kingdom of Jordan.[2]
Hashemite | |
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General | |
Category | Chromate minerals |
Formula (repeating unit) | Barium Chromate Ba(S,Cr)O4 |
Crystal system | Orthorhombic |
Identification | |
Color | Brown to yellow |
Cleavage | Perfect {001}, good {010} {100} |
Mohs scale hardness | 3.5 |
Luster | Adamantine |
Diaphaneity | Translucent |
Specific gravity | 4.54 - 4.59 |
References | [1] |
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