Almost all of the previous investigations of S 32 /S 34 ratios of sulfide minerals and ores have indicated a lack of significant variations in the ratios of specimens collected from one deposit. Most of these valuable previous studies have been done by non-geologists upon, unfortunately, limited and poorly representative mineral suites of sulfide deposits with little regard for the geologic occurrence and paragenesis of the sulfides present in the given deposit.This study of S 32 /S 34 ratios obtained from two or more sulfides occurring in one hand specimen indicates that appreciable variations, greater than four percent in one example, are evident. Therefore, a partial attempt is made to analyze the significance of variations in S 32 /S 34 ratios by means of a more detailed study of the genesis and the paragenetic relationships of the various sulfides present in selected specimens.The isotopic and geologic study of the selected specimens suggests the following: (1) a suggestion for distinguishing between exsolution and replacement is offered by isotopic ratios, (2) the mechanism of replacement of one sulfide by another is not always a diffusion mechanism of the small metal cations but also includes an exchange of the large sulfur anions, (3) hypogene ore fluids, giving rise to a vein, may vary in isotopic composition as indicated by an isotopic study of the minerals formed, and (4) the isotopic reactions that take place during supergene enrichment suggest that supergene and hypogene minerals can be distinguished by isotopic analyses. Other suggestions and avenues of investigation are also discussed.

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