Chad Liber, age 13, of Portland, Ore., for his question?

HOW IS SOAPSTONE FORMED?

Soapstone is a soft rock composed mostly of the mineral talc. It feels soapy or oily and varies from white to gray and grayish green. Soapstone is formed in the earth by changes in the structure and composition of an igneous rock such as peridotite. These changes occur at low temperature and moderate pressure in the presence of water.

Other rocks that usually occur along with soapstone include dolomite and serpentinite. Soapstone is a metamorphic rock that forms in layers that vary greatly in thickness.

The United States ranks among the world's leading soapstone producers. Deposits can be found in several states including California, New York, North Carolina and Virginia.

Other countries that produce soapstone include Canada, France and Italy.

Soapstone has many industrial uses. It is a good electric insulator and can easily be cut into various shapes. Because soapstone is not affected by high temperatures or acids, it is used for laboratory table tops, sinks and some chemical equipment.

Powdered soapstone is added to cosmetics, paper and paint as a filler to improve these products. Soapstone gives paper a smooth surface, for example. Tailors use pieces of soapstone called French chalk to mark cloth.