Soapstone

Soapstone most often forms at convergent plate boundaries, where peridotites, dunites and serpentinites are metamorphosed by heat and directed pressure; it can also form where siliceous dolostones are altered by hot, chemically active fluids. Talc occurs worldwide, often with serpentine, including many localities in the United States and in India, China, Australia, Zimbabwe, Canada and Russia; Egypt has an ancient deposit.

Soapstone feels greasy or soapy, and talc is so soft (Mohs 1) that it can be scratched easily and leaves a white powder when rubbed against other objects. Pyrophyllite-rich rocks (sold, for example, as "wonderstone" or agalmatolite) are virtually indistinguishable from talc by eye and are often sold together with soapstone; alabaster and serpentine carvings are also sometimes called soapstone. According to Pascle's published laboratory report, its pink soapstone beads carry a surface wax coating.

People have quarried soapstone for thousands of years. Native Americans in eastern North America made bowls, cooking slabs, pipes and ornaments from it as early as 3,000 to 5,000 years ago, and people on the California coast paddled to San Clemente Island for it as early as 8,000 years ago. In Scandinavia it was carved into molds for casting metal and into cooking pots, and Inuit carvers work fine-grained steatite. The Christ the Redeemer statue in Rio de Janeiro is faced with soapstone.