metamorphic
Soapstone
Steatite (composed primarily of Talc: Mg3Si4O10(OH)2)
Hardness: 1-2.5 on Mohs scale (very soft, can be scratched by a fingernail). Color: Gray, greenish-gray, or white with mottled patterns. Luster: Greasy or waxy to dull. Crystal structure: Monoclinic (usually massive/foliated). Cleavage: Perfect basal (though often appears massive). Specific gravity: 2.7–2.8.
- Hardness
- 1-2
- Color
- Gray, greenish-gray, or white with mottled patterns
- Luster
- Greasy or waxy to dull
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 1-2.5 on Mohs scale (very soft, can be scratched by a fingernail). Color: Gray, greenish-gray, or white with mottled patterns. Luster: Greasy or waxy to dull. Crystal structure: Monoclinic (usually massive/foliated). Cleavage: Perfect basal (though often appears massive). Specific gravity: 2.7–2.8.
Formation & geological history
Formed through the regional or contact metamorphism of ultramafic igneous rocks (like peridotite) or siliceous dolostones in the presence of water and heat, resulting in magnesium-rich silicate minerals. Many deposits are hundreds of millions of years old, dating to the Proterozoic or Paleozoic eras.
Uses & applications
Used for kitchen countertops and sinks due to heat resistance and non-porosity; carving material for sculptures; electrical insulators; and traditionally for cooking slabs or wood-burning stoves.
Geological facts
Soapstone is known for its incredible thermal mass, allowing it to absorb and radiate heat for long periods. It is chemically inert, meaning it won't react with acids like lemon juice or vinegar, making it ideal for laboratory tables.
Field identification & locations
Identify in the field by its distinct 'soapy' or greasy feel and extreme softness (easily scratched by a pocket knife or fingernail). It is commonly found in metamorphic belts in the Appalachian Mountains, Brazil, Finland, and India. Look for a dense, heavy feel relative to its soft texture.
More like this
