Soapstone

Soapstone, also known as steatite, was a soft and brittle but easily worked hardstone.

Description
This harder version of talc was found in colors ranging from white to green and was often dyed other colors. Easily worked by unskilled hands for low-detail carving, it could hold intricate patterns but was not hard enough to hold delicate shapes. It could be easily polished to a warm, glossy finish. A typical price was 9 sp per lb (20 sp per kg).

Powers
Colloquial wisdom gave soapstone some mystical properties involving fire or capturing warmth, but these have not yet been proven.