Soapstone (also known as steatite or soap rock) is a metamorphic rock, a talc-schist. It is largely composed of the mineral talc and is thus rich in magnesium. It is produced by dynamo thermal metamorphism and metasomatism, which occurs in the areas where tectonic plates are sub ducted, changing rocks by heat and pressure, with influx of fluids, but without melting. It has been a medium for carving for thousands of years
Physical Properties of Soapstone:
Soapstone is composed primarily of talc and shares many physical properties with that Mineral. These physical properties make soapstone valuable for many different uses. These useful physical properties include:
- Soft and very easy to carve
- Low electrical conductivity
- Heat resistant
- High specific heat capacity
- Resistant to acids and alkalis
Soapstone is a Rock, and its mineral composition can vary. Its composition depends upon the parent rock material and the temperature/pressure conditions of its metamorphic environment. As a result, the physical properties of the soapstone can vary from quarry to quarry and even within a single rock unit.
The level of metamorphism sometimes determines its grain size. Soapstone with a fine grain size works best for highly detailed carvings. The presence of minerals other than talc and the level of metamorphism can influence its hardness. Some of the harder varieties of soapstone are preferred for countertops because they are more durable than pure talc soapstone.
The special properties of soapstone make it suitable, or the material of choice, for a wide variety of uses. A number of examples of soapstone use are explained below and in the photograph captions on this page.
- Countertops in kitchens and laboratories
- Cooking pots, cooking slabs, boiling stones
- Bowls and plates
- Cemetery markers
- Electrical panels
- Ornamental carvings and sculptures
- Fireplace liners and hearths
- Wall tiles and floor tiles
- Facing stone
- Bed warmers
- Marking pencils
- Molds for metal casting
- Cold stones