A New Mineral from Tsumeb, Namibia
نویسنده
چکیده
Stibioclaudetite is a new mineral species with ideal chemistry AsSbO3. The symmetry is monoclinic, P21/n, with a 5 4.5757(4) Å, b 5 13.1288(13) Å, c 5 5.4216(5) Å, β 5 95.039(4)°, V 5 324.44(5) Å, Z 5 4, and dcalc 5 5.009 g/cm. The strongest X-ray lines (calculated) are 3.512 (100), 3.282 (82), 3.238 (71), 2.279 (34), and 4.995 (32). The average of ten microprobe analyses is 45.15% As2O3 and 55.77% Sb2O3, total 100.92, corresponding to As1.088Sb0.912O3. Stibioclaudetite forms adamantine, colorless transparent bladed crystals to 6 mm, bound by {010}, {110}, {111}, and {101}. The mineral is flexible with perfect cleavage on {010}. The hardness is 2 and has refraction indices 2.00. Stibioclaudetite occurs with leiteite, ludlockite, smithsonite and quartz in a vug within massive tennantite from the Tsumeb mine, Tsumeb, Namibia. Stibioclaudetite is isostructural with claudetite, specifically an Sb-substituted ordered analog, and the name denotes the relationship. The crystal structure consists of corrugated sheets of corner-sharing AsO3 and SbO3 trigonal pyramids arranged in an ordered, alternating pattern. Raman spectra of stibioclaudetite, claudetite, and leiteite are presented and compared. Stibioclaudetite AsSbO3 A New Mineral from
منابع مشابه
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