Algodonite

Formula:  Cu₆As

Origin of name:  After locality; Algodones silver mine, Coquimbo, Chile

Crystal system:  Hexagonal

Crystal class:  6/m 2/m 2/m

Twinning:

Unit cell: a = 2.600 Å, c = 4.228 Å

Colour:  Silver-white to steel-gray; tarnishes rapidly to dull brown

Diaphaneity: Opaque

Luster:  Metallic

Habit:  Crystals sharp, distorted; usually massive; granular

Hardness:  4

Specific gravity:  8.38

Cleavage:  None

Tenacity:

Streak:

Synonyms/varieties: none

Comments: in hydrothermal deposits, intimately associated with other copper arsenides