The crystal-chemistry of Vietnamese talcs from the Thanh Son district (Phu Tho province, Vietnam).

The mineralogy and crystal chemistry of a new talc ore deposit situated at Thu Ngac commune, Thanh Son district, Phu Tho province, Vietnam, was investigated using X-ray fluorescence, electron microprobe, X-ray diffraction, Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance (29Si and 1H) and colorimetry. Both chemical and crystal-chemical analyses showed that the talcs from the Phu Tho province are very pure because they contain few accessory minerals (chlorite, amphibole and goethite) and few substitutions of Si by Fe and Al in their crystal structure. The talc ore may well meet the standards required for a wide range of industrial applications. [ABSTRACT FROM AUTHOR]