Linnaeite

Formula:  CoCo₂S₄

Origin of name:  For C. Linnaeus, Swedish taxonomist

Crystal system:  Cubic

Crystal class:  4/m -3 2/m

Twinning:  On {111}

Unit cell: a = 9.435 Å

Colour:  Light gray to steel-grey, rapidly tarnishes copper-red

Diaphaneity: 

Luster:  Metallic

Habit:  Crystals octahedral; massive, compact to granular

Hardness:  4.5 to 5.5

Specific gravity:  4.8 to 5.0

Cleavage:  1; {001} imperfect

Tenacity:  Subconchoidal to uneven

Streak: 

Synonyms/varieties:

Comments:  Series with polydymite