Tongbaite

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Tongbaite
General
CategoryCarbide mineral
Formula
(repeating unit)
Cr3C2
Strunz classification1.BA.15
Crystal systemOrthorhombic
Crystal classDipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space groupPnma
Unit cella = 5.52 Å, b = 11.48 Å
c = 2.82 Å; Z = 4
Identification
ColorPale brownish yellow; pale violet in reflected light
Crystal habitPrismatic crystals, pseudohexagonal
TenacityBrittle
Mohs scale hardness9.6
LusterMetallic
DiaphaneityOpaque
Specific gravity6.64 calculated
References[1][2][3]

Tongbaite is a rare mineral that has the chemical formula Cr3C2, or chromium carbide.

It was first described in 1983 for an occurrence in Liu village, Tongbai County (桐柏县), Henan Province, China and named for the locality.[2] It occurs in an ultramafic rock deposit.[1] It has also been reported from the Tibet Autonomous Region and from the Isovsky District in the Urals of Russia.[2]

References[edit]