Proustite

Proustite crystals

Description

A bright red mineral composed of silver arsenic sulfide. Proustite was named after the 18th century French chemist, Joseph L. Proust. It is often associated with silver mines and occurs in Canada, Mexico, the United States (Colorado, Nevada, Idaho), Peru, Russia and Australia. The ruby color turns dark with exposure to light. An old name for proustite is ruby silver.

Synonyms and Related Terms

ruby silver; silver arsenic sulfide; prouestita (Esp.); Proustit (Deut.)

Physical and Chemical Properties

• Hexagonal crystal system.
• Good cleavage in one direction.
• Fracture = conchoidal to uneven.
• Luster = adamantine to submetallic.
• Streak = bright red.

Composition	Ag3AsS3
Mohs Hardness	2 - 2.5
Density	5.6 g/ml

Resources and Citations

• Mineralogy Database: Proustite

• Susan E. Schur, Conservation Terminology: A review of Past & Current Nomenclature of Materials, Technology and Conservation, Spring (p.34-39); Summer (p.35-38); Fall (p.25-36), 1985

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 642

• C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979