The Devonian massive sulfide orebodies of the West Shasta district in northern California are composed primarily of pyrite, with lesser amounts of other sulfide and gangue minerals. Examination of polished thin sections of more than 100 samples from the Mammoth, Shasta King, Early Bird, Balaklala, Keystone, and Iron Mountain mines suggests that mineralization may be divided into six paragenetic...

It is shown that the antisymmetry of the sphalerite structure is isomorphous to the coloured diamond group Fd'3'm if sites associated with positive and negative charge are regarded as being equivalent except for colour. This methodology enables the multiplicity and polarity of external crystal surfaces to be deduced readily. In addition this analysis is shown to be very useful for the analysis ...

Mississippi Valley-type (MVT) ore deposits arc epigenetic carbonate-hosted Pb-Zn deposits that contain galena, sphalerite, fluorite, bar&e, dolomite, calcite, and quartz. Although they are thought to form from basinal brines, their exact origins are still unclear, partly because of the scarcity of reliable geochronological data. Rb-Sr dating of sphalerites has recently been shown to be a promis...