Caswellsilverite

Formula:  NaCrS₂

Origin of name:  For Caswell Silver, American mineralogist

Crystal system:  Hexagonal

Crystal class:  -3 2/m

Twinning: lamellar, probably as a result of pressure-induced deformation

Unit cell: a = 3.55 Å, c = 19.5 Å

Colour:  Yellow grey in reflected light

Diaphaneity:  Opaque

Luster:  Metallic

Habit:  Anhedral grains

Hardness:  2

Specific gravity:  3.21

Cleavage:  None

Tenacity:

Streak:

Synonyms/varieties:

Comments:  From a meteorite as inclusions in enstatite crystals in the brecciated matrix, also between coarse pyroxene crystals in chondrules in a meteorite