Argentiferous Roquesite (CUInS2) From the Tosham Tin Prospect, Bhiwani District, Haryana

The sheared rhyolite-metasediment contact of the Tosham Hill is well-mineralised with disseminations and thin veins of very fine grained pyrite, pyrrhotite, chalcopyrite, sphalerite, galena, cassiterite, stannite, bismuthinite, rutile, hematite, wolframite and roquesite. Roquesite occurs intimately associated with chalcopyrite and is replacing it. The approximate reflectance of roquesite in white light measured in air was 20.7% and its average Vickers microhardness value was 229. Qualitative analysis of roquesite carried out with the help of the Laser microanalyser showed presence of major amounts of copper and indium and minor amount of silver. Based on the physical, optical and micro-chemical data, roquesite has been identified as the argentiferous variety, This is the first report of the occurrence of roquesite from India.