Duranusite

Formula:   As₄S

Origin of name:   Locality; Duranus, Alpes-Maritimes, France

Crystal system:   Orthorhombic

Crystal class:   Unknown

Twinning:

Unit cell: a = 3.576 Å, b = 6.759 Å, c = 10.074 Å

Colour:  Red

Diaphaneity: Opaque

Luster:   Metallic

Habit:   Tiny grains, randomly oriented fibers and wiry aggregates

Hardness:   2

Specific gravity:   4.50

Cleavage:   None

Tenacity: 

Streak: 

Synonyms/varieties:

Comments: Found in calcite veinlets in marls and siliceous limestone in assocation with arsenic, realgar, orpiment and stibnite