Characterization of talc and associated minerals

The unequivocal identification of mineral impurities in talc requires definitive analytical techniques due to the very similar structure of many naturally occurring silicates and the small quantities of associated minerals frequently found. The instrumental methods and techniques extant for this purpose are reviewed. Light microscopy, x-ray diffractometry, and differential thermal analysis have been found to be particularly useful, complementary, and practical for both exploratory and routine determinations of mineral impurities in the talc matrix. When necessary, transmission electron microscopy is recommended for the analysis of mineral components present at sub-trace levels.