Soapstone is a metamorphic rock. It is largely composed of the mineral talc, and thus, is rich in magnesium. Soapstone is relatively soft because of its high talc content (talc has a definitional value of one on the Mohs hardness scale). There is no fixed hardness for soapstone because the amount of talc it contains varies widely, from as little as 30% for architectural grades, such as those used on countertops, to as much as 80% for carving grades.
What makes soapstone a great countertop?
1. It doesn’t stain. Soapstone is dense and nonporous; it does darken when liquid pools on its surface, but it lightens back up when the liquid evaporates or is cleaned off.
2. It can stand up to acidic materials. The fact that soapstone is chemically inert means it’s not harmed by lemon juice or cleaners that must be avoided with other natural stone surfaces. That’s why it’s so popular for use as science lab tops.
3. It’s heat resistant. The density of soapstone makes it an amazing conductor of heat, which enables it to withstand very high heat with no damage. You can put hot pans right on the surface without worry.