Carlinite

Formula:  Tl₂S

Origin of name:  For locality; Carlin gold deposit, Nevada

Crystal system:  Hexagonal

Crystal class:  -3

Twinning:

Unit cell: a = 12.12 Å, c 18.175 Å

Colour:  Dark grey, blackens on exposure

Diaphaneity: Opaque

Luster:  Metallic to dull

Habit:  Subhedral to anhedral grains

Hardness:  1

Specific gravity:  8.1

Cleavage:  2; { 0001} perfect; prismatic cleavage imperfect

Tenacity: Hackly fracture

Streak:  Dark grey to black

Synonyms/varieties:

Comments: Found in the east pit of the Carlin Mine, Eureka Co., Nevada, U.S.A. as small grains in brecciated fragments of carbonaceous limestone, result of epithermal mineralization