Talc/Soapstone
Ground Calcium Carbonate (CaCo₃) 
Dolomite
China Clay

TALC
Talc has the formulae Mg₃Si₄O₁₀(OH)₂ and a relative hardness of 1. It is a mineral of secondary origin formed by the alteration of magnesium silicates. Usually found in metamorphic rocks where, in a non-crystalline form, it occurs as 'soapstone' - and can make up large rock masses. Used for laboratory table tops and for many industrial uses. It has a greasy feel.

Soapstone
Soapstone is massive Talc which occurs as a secondary mineral formed as a result of the alteration of olivine, pyroxene, and amphibole.

It occurs along faults in magnesium-rich rocks. It occurs less frequently as a result of thermal metamorphism of dolomitic limestones.

It's distinguishing features are extreme softness, soapy feel, and greenish white colour. Because of its softness it has often been used for carving into artifacts such as figurines.