Zincochromite

Zincochromite is a zinc chromium oxide mineral with the formula ZnCr₂O₄. It is the zinc analogue of chromite, hence the name. It was first described in 1987 as an occurrence in a uranium deposit near Lake Onega, Russia.^[4] It has also been reported from Dolo Hill, New South Wales, Australia, and from the Tarkwa Mine in the Ashanti gold belt of Ghana.^[2]

Zincochromite
Zincochromite found in Russia
General
Category	Spinel group
Formula	ZnCr2O4
IMA symbol	Zchr[1]
Strunz classification	4.BB.05
Crystal system	Cubic
Crystal class	Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m)
Space group	Fd3m
Unit cell	a = 8.32 Å; Z = 8
Identification
Color	Brownish black
Crystal habit	Zoned euhedral crystals with hexagonal outline
Mohs scale hardness	5.8
Luster	Semimetallic
Streak	Brown
Diaphaneity	Opaque, translucent in thin slivers
Optical properties	Isotropic
Other characteristics	Weakly paramagnetic
References	[2][3][4][5]