Mineragraphy of Gold-Quartz-Sulphide Reefs of Hutti Gold Mines, Raichur District, Mysore State

The gold deposits at Hutti situated on the north western fringe of Hutti-Maski Schist belt are of gold-quartz-sulphide reef type. A detailed study has shown three distinct stages of mineralization. Minerals formed during the first stage are rutile, pyrite (with traces of gold) arsenopyrite, specularite, quartz (reef and vein type) and carbonate. Minerals of the second stage are pyrrhotite. chalcopyrite, sphalerite. galena and gold. Minerals of the third stage are pyrite, calcite and quartz found along numerous minor faults (slips) and major faults. Based on the textural and associational criteria, three generations of gold are distinguished. They are: 1. Gold-pyrite association. 2. Gold-aresenopyrite-quarrz association. 3. Gold-sphalerite-quartz association. The study has further shown that only the gold of the second and third generations constitute the lode. Gold is in the native state and no tellurides are present.