particles per cubic foot over an 8-hour workday. The National Institute for Occupational Safety and Health has set a recommended exposure limit of 6 mg/m3 total exposure and 3 mg/m3 respiratory exposure over an 8-hour workday. At levels of 3000 mg/m3, soapstone is immediately dangerous to life and health. Other names The local names for the soapstone vary: in Vermont, name "grit" is used, in Georgia "white-grinding" and "dark-grinding" varieties are distinguished, California has "soft", "hard", and "blue" talc. Also: Combarbalite stone, exclusively mined in Combarbalá, Chile, is known for its many colors. While they are not visible during mining, they appear after refining. Palewa and gorara stones are types of Indian soapstone. A variety of other regional and marketing names for soapstone are used. Gallery See also List of minerals List of rocks Talc carbonate Archeological Site 38CK1, Archeological Site 38CK44, and Archeological Site 38CK45 References Sources Further reading Felce, Robert (2011) Soaprock Coast... The origins of English porcelain External links Soapstone Calculated Refractory Data w/ Technical Properties Converter (Incl. Soapstone Volume vs. Weight measuring units) Ancient soapstone bowl (The Central States Archaeological Journal) Soapstone Native American quarries, Maryland (Geological Society of America) Prehistoric soapstone use in northeastern Maryland (Antiquity Journal) The Blue Rock Soapstone Quarry, Yancey County, NC (North Carolina Office of State Archaeology) CDC - NIOSH Pocket Guide to Chemical Hazards Steatite historical marker in Decatur, Georgia Dielectrics Metamorphic rocks Phyllosilicates Sculpture materials Stone (material) Petrology Ceramic materials