Pyrophyllite is a phyllosilicate mineral composed of aluminium silicate hydroxide: Al2Si4O10(OH)2. It occurs in two more or less distinct varieties, namely, as crystalline folia and as compact masses; distinct crystals are not known.
Pyrophyllite occurs in phyllite and schistose rocks, often associated with kyanite, of which it is an alteration product. It also occurs as hydrothermal deposits. Typical associated minerals include: kyanite, andalusite, topaz, mica and quartz.
<h2>Pyrophyllite</h2> is easily machineable and has excellent thermal stability. Therefore it is added to clay to reduce thermal expansion when firing but it has many other industry uses when combined with other compounds, such as in insecticide and for making bricks. Pyrophyllite is also widely used in high-pressure experiments, both as a gasket material and as a pressure-transmitting medium.
<h2>Pyrophyllite</h2> is used for ceramics, in paints, insecticides, and in the production of rubber. It is also used as a minor ornamental stone for carvings and sculptures.
