"Rock of the Month # 85, posted for July 2008" ---
A fine sample of pale butterscotch-coloured calcite displaying fine rhombohedral crystal form. The crystal surfaces have a waxy lustre, and the featured rhomb, long axis 7 cm, displays both concentric growth bands and also twinning oblique to the long axis of the rhomb. Sample from Mina Teyahua, Terminal de Providencia, collected in 2002 by Irwin Kennedy.The varied crystal habits and mineral inclusions of calcite make this a popular mineral with collectors (Turley and Koval, 1987; Brock, 1993). Huizing et al. (2003) review the forms of calcite from around the world.
Brock,KJ (1993) The crystal forms of calcite. Mineral.Record 24, 451-461,470.
Huizing,T, Jarnot,M, Neumeier,G, Richards,RP and Schneider,G (editors) (2003) Calcite: the Mineral with the Most Forms. ExtraLapis English 4, Lapis International, 114pp. (see book critiques in Can.Mineral. 41, 1526-1527, 2003, and Mineralogical Record 36, 226-228, March 2005).
Turley,C and Koval,M (1987) The Miller calcite collection. Mineral.Record 18 no.6, 405-411.
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