The Talc
It has a fatty to pearly luster, is translucent to opaque and its colors range from white to gray or apple green. Talc results from the alteration of magnesium silicates such as pyroxenes, amphiboles, olivine, dolomite and other similar minerals. It is commonly found in metamorphic rocks.
A coarse gray-green talc, called soapstone or "soapstone", was used as material for ovens, sinks, power stations, etc.
Generality
This leads to sheet structures, hence an excellent cleavage. With as main examples: talc ; muscovite ; kaolin . Here are some minerals from this family: Antigorite, Biotite, Chlorite, Glauconite, Illite, Kaolinite, Lepidolite, Montmorillonite, Muscovite, Phlogopite, Prehnite, Pyrophyllite, Serpentine, Smectite, Talc, Vermiculite.