Calaverite

Calaverite, or gold telluride, is an uncommon telluride of gold; it is a metallic mineral. It was first discovered in Calaveras County, California in 1861. Its chemical formula is AuTe₂. Its color may range from a silvery white to a brassy yellow. It is closely related to the gold - silver telluride sylvanite. Another mineral containing AuTe₂ is krennerite.

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Physical properites

Calaverite occurs as monoclinic crystals, which do not possess cleavage planes. It has a specific gravity of 9.35 and a hardness of 2.5.

Chemical properites

Calaverite can be dissolved in concentrated sulfuric acid. In hot sulfuric acid the mineral dissolves, leaving a spongy mass of gold in a red solution of tellurium.

Occurences

Calaverite occurrences include Cripple Creek, Colorado; Calaveras County, California, USA (from where it gets its name); Nagyag, Romania; Kirkland Lake Gold District, Ontario; Rouyn District, Quebec; and Kalgoorlie, Australia.

In the Kalgoorlie gold rush of the 1890s, large amounts of calaverite were mistaken for fool's gold, and were discarded. The mineral deposits were used as a building material, and for the filling of potholes and ruts. Several years later, the nature of the mineral was identified, leading to a minor gold rush to excavate the streets.

See also

• List of minerals

References

• D. M. Chizhikov, V. P. Shchastlivyi, 1966, Tellurium and Tellurides, Nauka Publishing, Moscow
• Klein, Cornelis and Hurlbut, Cornelius S., 1985, Manual of Mineralogy 20th ed., p. 289, Wiley, ISBN 0-471-80580-7
• Fortey, Richard, 2004, The Earth, Harper Collins