The average cost of pyrophyllite per ton is $0.22-2.26. Its chemical formula is Al2Si4O10(OH)2. It is a phyllosilicate mineral composed of aluminum silicate hydroxide. It has a pearly luster. It occurs in white, pale green, grayish colors and is soft in texture. It has a specific gravity of 2.65-2.85. Compact pyrophyllite is used for manufacturing slate pencils and chalks. It is used in making small images, ornaments and carvings. It is also used in high-pressure experiments. It has great thermal stability.