Acanthite

From CAMEO
Revision as of 07:24, 24 July 2013 by (talk)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Description

A gray to black metallic mineral of silver sulfide. Acanthite occurs in hydrothermal deposits and as a corrosion product of silver. Large crystals of acanthite have been mined in Norway (Kongsberg), Mexico (Pachuca, Guanajuato, Zacatecas) and the U.S. (Nevada, Colorado, Montana). On silver, acanthite crystals can appear as black, shiny, acanthus-like leaflets. At temperatures above 173 C, acanthite is converted to argentite.

Synonyms and Related Terms

acanthus

Chemical structure

Acanthite.jpg


Other Properties

Luster = metallic Streak = black Cuts like lead; indistinct cleavage

Composition Ag2S
CAS 21548-73-2
Mohs Hardness 2.0 - 2.5
Melting Point 845
Density 7.2 - 7.4
Molecular Weight mol. wt. = 247.8

Hazards and Safety

Sensitive to light.

Fisher Scientific: MSDS

Additional Information

Mineralogy Database: Acanthite

Authority

  • Encyclopedia Britannica, http://www.britannica.com Comment: argentite" [Accessed December 11, 2001 (gives conversion temperature as 91 C)
  • C.W.Chesterman, K.E.Lowe, Audubon Society Field Guide to North American Rocks and Minerals, Alfred A. Knopf, New York, 1979 Comment: Gives conversion temperature as 173 C

Retrieved from "http://cameo.mfa.org/index.php?title=Acanthite&oldid=27130"