Variation of Rhenium Contents in Molybdenites from the Sar Cheshmeh Porphyry Cu‐Mo Deposit in Iran

This paper presents the results of a study on the variation of Re in the Sar Cheshmeh porphyry copper‐molybdenum deposit in Iran. The Re content was determined in monomineralic molybdenite separates from veinlets and from molybdenum milled floatation concentrates. Mineralogical data and chemical analyses indicate two generations of veinlet molybdenites in the Sar Cheshmeh deposit. The first generation (molybdenite I), which contains low Re, is found as intergrowth with quartz in silicified rocks with low total sulfide content, and the second generation (molybdenite II), which contains high Re, is found in veinlets with low quartz content. There is a positive correlation between the elevation of molybdenite deposition and Re content. Decrease in the temperature and pH of the hydrothermal fluids are effective for the accumulation Re in molybdenite. X‐ray diffraction study of 14 molybdenite samples indicate that the molybdenites are of the 2H polytype.