Nearly isostructural sulfide species sharing the I4#-2m and I4#- space groups; with a structure that is almost identical to that of the Sphalerite Group species. The general formula is A^2BCX^4 where A = Ag, Cu; B = Cu, Ce, Fe, Hg, Zn; C = As, Ge, In, Sb, Se, Sn and X; and X = S, Se. (Where both the A and B positions are occupied by Cu the formula is typically written A^3BX^4; but using the formula as stated above clarifies the structural position of Cu in the B position.) [Note: Dana 8th classifies Famatinite, Luzonite, and Permingeatite as Sulfosalts rather than as Sulfides; but Fleischer's Glossary, 1999, places them within the Stannite Group. An examination of their reported characteristics suggest the latter to be the better classification.] |
