CHEMISTRY - Mg3Si4O10(OH)2
CRYSTALLOGRAPHY - Monoclinic or Triclinic
CRYSTAL GROWTH AND HABITS - Crystals of Talc are platy to tabular and sometimes pseudotrigonal. It typically forms compact masses but can also be fibrous.
COLOR AND OPTICAL PROPERTIES - Color varies from whit through dark green, brown or pinkish.
HARDNESS - 1
SPECIFIC GRAVITY - 2.58 - 2.83
LUSTER - Pearly, greasy or dull
STREAK - White
BREAKABILITY - Perfect cleavage along {001} and it is sectile.
OCCURRENCE - Talc occurs in altered mafic rocks. It can also be formed by low temperature metamorphism of silica rich dolomites.
ASSOCIATED MINERALS - Serpentine, Actinolite, Tremolite, Pyroxene, Chlorite, Anthophyllite, Dolomite, Calcite
MINERAL NAME - Questionable origin, but probably from Arabic.