Talc is also called steatite (it is a magnesium silicate hydrate). It is the main component of soapstone, it is the softest of all minerals (Mohs hardness of 1). Its silicate layers are weakly bound, this is the reason for the characteristic greasy or soapy feeling. Its color depends on the impurities (it can be colourless, white, grey, green, yellow or pink). It often it has a mother-of-pearl sheen.
Soapstone Steatite Carving
Talc Mineralogy at Mondo Minerals