OCCURRENCE OF ARSENOSULVANITE AT THE BOR COPPER-DEPOSIT, EASTERN SERBIA, YUGOSLAVIA

An anisotropic variety of arsenosulvanite from the Bor copper deposit in Eastern Serbia, Yugoslavia, was investigated. This mineral occurs a s a product of the metasomatic processes replacing enargite. Reflected light color is white-yellow, without pronounced bireflectance. Anisot ropism is moderate to distinct in light-green and brownish tints. Thes e effects reveal mimetic lamellar twinning in the grains and granular texture of aggregates. The empirical formula, Cu12.41(AS2.75,Ge0.13,V1 .04)3.92S15.67, was based on the average of five EDS microprobe analys es. The indexed X-ray powder diffraction pattern is reported. Indexing is based on a primitive cubic cell, space group P43mBAR. Refined latt ice parameter: a - 10.551(4) angstrom, Z = 2, calculated density; D(x) = 4.398 g/cm3.