Bénavidésite

Formula:  Pb₄ (Mn, Fe) Sb₆ S₁₄

Origin of name:  For A. Benavides, Peru, for his contributions to development of mining in Peru

Crystal system:  Monoclinic

Crystal class:  2/m

Twinning: polysynthetic common parallel to elongation

Unit cell: a = 15.74 Å, b = 19.14 Å, c = 4.06 Å, b = 91.5°

Colour:  Lead-gray

Diaphaneity: Opaque

Luster:  Metallic

Habit:  Microscopic crystals

Hardness:  2.5 to 3

Specific gravity:  5.6

Cleavage:  None

Tenacity:

Streak:  Brownish gray

Synonyms/varieties:

Comments:  Series with jamesonite. Found in metamorphosed iron sulfide deposit with submarine felsic volcanism, in telescoped polymetallic mineralisations associated with dacitic intrusions