Formula: Cu₁₃VAs₃S₁₆

Species:

Colour: Bronze, pinkish bronze

Lustre: Metallic

Hardness: 3 – 4

Specific Gravity: 4.2 – 4.5

Crystal System: Isometric

Member of: Germanite Group

Name: Named by R. E. Landon and A. H. Mogilnor in 1933 after the type locality, the East Colusa Mine in Butte, Montana – USA.

Co-Type Localities: Lebedinoe Au Deposit (Nezametnyi Mine), Aldan, Sakha, Russia. East Colusa Mine, Butte Mining District (Summit Valley Mining District), Silver Bow County, Montana – USA