Niningerite

General
Category	Sulfide minerals
Formula (repeating unit)	MgS
Strunz classification	2.CD.10
Crystal system	Cubic
Crystal class	Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m)
Space group	Fm3m
Unit cell	a = 5.2 Å; Z = 4
Identification
Color	grey
Mohs scale hardness	3½ - 4
Luster	metallic
Diaphaneity	opaque

Niningerite is a magnesium-iron-manganese sulfide mineral with the chemical formula MgS that is found in enstatite chondrite meteorites. Niningerite is the magnesium-dominant analog of keilite. This mineral is named after Harvey H. Nininger.