Aschamalmite

Formula:  Pb₆Bi₂S₉

Origin of name:  After locality, Ascham Alm, Untersulzbachtal, Salzberg, Austria

Crystal system:  Monoclinic

Crystal class:  2/m, 2 or m

Twinning:

Unit cell: a = 13.71 Å, b = 4.09 Å, c = 31.43 Å, β = 91.0°

Colour:  Lead-gray

Diaphaneity: Opaque

Luster:  Metallic

Habit:  Crystals prismatic, lath-like or plate-like

Hardness:  3.5

Specific gravity:  7.33 (calculated)

Cleavage:  1; {001} perfect

Tenacity:

Streak:

Synonyms/varieties: Beegerite

Comments: Found in alpine-cleft veins, cutting gneisses