gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1979.043.325.12 Definitive Data on Bohdanowiczite, a New Silver Bismuth Selenide Banaś M. Academy of Mining and Metallurgy, Institute of Geology and Mincral Deposits, Cracow, Poland Atkin D. Bowles J. F. W. Simpson P. R. Geochemical Division, Institute of Geological Sciences, 64/78 Gray's Inn Road, London WC1X 8NG 3 1979 43 325 131 133 2 6 1978 14 9 1978 Copyright © 1979, The Mineralogical Society 1979 Summary

Bohdanowiczite was first described in 1967 but incomplete data prevented its acceptance as a new mineral at that time. Additional data on the same material now characterize bohdanowiczite as a new species with the formula:

3[(Ag0.98Cu0.02)0.97(Bi0.97Pb0.03)1.02(Se0.83S0.17)2.01]

The mineral occurs in intimate intergrowths with clausthalite and wittichenite in polymetallic mineralization at Kletno in Poland. In reflected light bohdanowiczite has a creamy-yellow colour and short polysynthetic twinning is frequently observed. Cell parameters indexed on a hexagonal lattice are a = 4.183±0.008 Å and c = 19.561± 0.016 Å. P¯3m1 is the most likely space group. The strongest lines of the powder pattern are 2.91(100), 2.03(30), 3.40(20), 6.54(20), 2.09(18), 3.26(18). The calculated density is 7.72 gm/cm3 and the VHN between 63 and 96 kg/mm2.