Tongbaite

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Tongbaite
General
Category Carbide mineral
Formula
(repeating unit)
Cr3C2
Strunz classification 01.BA.15
Crystal symmetry Orthorhombic dipyramidal
H-M symbol: (2/m 2/m 2/m)
Space group: P nma
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
Crystal system Orthorhombic
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]