Hodrushite

Formula:  Cu₈Bi₁₂S₂₂

Origin of name:   After locality; Banska-Hodrusa, Slovakia

Crystal system:  Monoclinic

Crystal class:  2/m

Twinning: 

Unit cell: a = 27.21, b = 3.93, c = 17.58, Å = 92.15°

Colour:  Steel-gray with faint yellowish tint; rapidly tarnishes to brownish bronze

Diaphaneity:  Opaque

Luster:  Metallic

Habit:  Crystals acicular, tiny, sometimes platy or columnar striated vertically; fine-grained aggregates; irregular grains

Hardness:  3 to 3.5

Specific gravity:  6.35

Cleavage:  None

Tenacity: Uneven fracture

Streak: Grayish black

Synonyms/varieties:

Comments: