Tongbaite

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Tongbaite
General
Category Carbide mineral
Formula
(repeating unit)
Cr3C2
Strunz classification 1.BA.15
Crystal system Orthorhombic
Crystal class Dipyramidal (mmm)
H-M symbol: (2/m 2/m 2/m)
Space group Pnma
Unit cell a = 5.52 Å, b = 11.48 Å
c = 2.82 Å; Z = 4
Identification
Color Pale brownish yellow; pale violet in reflected light
Crystal habit Prismatic crystals, pseudohexagonal
Tenacity Brittle
Mohs scale hardness 9.6
Luster Metallic
Diaphaneity Opaque
Specific gravity 6.64 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, 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]