Abstract:Ge-, Sn-bearing sulvanite, a variety of sulvanite, occurs in the Gacun Agbearing polymetallic ore deposit, Sichuan Province. It is normally square, rectangular or irregular in form and light lemon yellow in color; its grain sizes are commonly 0.01-0.1 mm with the greatest being 0.3 mm. Microhardness 137.8kg/mm2, equivalent to 3.49 on Mohs hardness scale; reflectance 31.54% (589 nm). The main chemical components are Cu 52.29-54.71%, S 30.59-32.49%, V 5.70-6.50%, Ge 4.3-6% and Sn 2.43-3.65%, with trace amounts of Zn, Fe, As, Sb and Bi, giving a simplified formula of Cu3 (V,Ge, Sn) S4. The mineral is of cubic system, a0=10.66A, V=1211.36A3, with space group P3m.