Sixty-seven pyrite samples from in and near the Endako molybdenum mine were analyzed for 11 minor elements (Ag, Ba, Bi, Co, Cu, Mn, Ni, Pb, Sn, Sr, and Zu) by quantitative emission spectrography. All elements were found to have density distributions closely approaching a log-normal model or a mixture of two log-normal populations. Studies of individual elements did not appear to provide adequate insight. into their significance. However, Q-mode factor analysis produced a threefactor model that could be integrated easily with existing geological knowledge of the deposit. These three factors account for more than 94 percent of the variance in the data. Factors 1 and 2 correlate spatially with the ore zone and a southerly pyrite zone, respectively, and are interpreted as reflecting the variable chemical nature of mineralizing fluids during high temperature (ore) metallization and lower temperature (pyrite zone) metallization, respectively. This interpretation is consistent with independent data on wall rock alteration and temperature of filling of fluid inclusions in vein quartz. Factor 3 is interpreted as a background feature relating to the host. The first three factors of an R-mode analysis correspond with Q-mode results but the overall R-mode model is less acceptable for statistical and subj,ective reasons.The results appear to have practical potential in the economic evaluation of large areas containing scattered outcrops mineralized with pyrit.e and other minerals.