Talc
Talc (from the Arabic talk) is a silicate mineral, a type of clay. It is the standard for grade 1 in the Mohs scale of mineral hardness. A fingernail can easily scratch it. Talc is composed of hydrated magnesium silicate with the chemical formula Mg3Si4O10(OH)2. Talc and pyrophyllite are very similar, but pyrophyllite may be slightly harder.

Crystals of talc
Talc has a greasy feel and a translucent, soapy look. In loose form, it is the widely used substance known as talcum powder. Steatite, also called soapstone, is a rock with a lot of talc.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.