Talc products are described as platy talc, containing predominately (>90%) the mineral talc; or tremolitic talc, most often a
natural blend of talc, tremolite, serpentine and anthophyllite. Platy talcs can be further classified as microcrystalline or
macrocrystalline. Microcrystalline varieties are naturally small in plate size and comprise compact, dense ores. Macrocrystalline
varieties contain relatively large, higher aspect ratio plates. The term fibrous talc has in the past been used in reference to tremolitic
talc, but this is a distinct misrepresentation.
Talc products are also categorized by geographic origin, which reflects characteristic mineralogy (see Table 1). The
so-called western platy talcs, from Montana and Texas, are microcrystalline, with chlorite as a characteristic accessory mineral.
Eastern platy talcs, from Vermont and Canada, are macrocrystalline, with carbonates as characteristic accessory minerals, as is the
Chinese talc that is readily available in North America.