Pierrotite

Formula: Tl₂Sb₆As₄S₁₆

Origin of name: for R. Pierrot, French geologist

Crystal system: orthorhombic

Crystal class: mm2

Twinning: 

Unit cell: 

Colour: grayish black

Diaphaneity: transparent

Luster: metallic

Habit: massive, crystalline aggregates

Hardness: about 3.5

Specific gravity: 4.97

Cleavage: none

Tenacity: 

Streak: 

Synonyms/varieties:

Comments: dimorphous with parapierrotite