Image: <a rel="nofollow" class="external text" href="http://www.mindat.org/user-13767.html#0">John Krygier</a> (Public domain)
monocliniccommonSilicates
Talc
Mg₃Si₄O₁₀(OH)₂
This specimen displays talc in a botryoidal (grape-like) habit, characterized by its soft, greasy feel and typically pale coloration. The surface shows a pearly luster on the rounded forms.
Talc Physical Properties
Mohs Hardness
1Crystal System
monoclinicLuster
pearlyStreak Color
whiteCleavage
Perfect basal cleavage on {001}Fracture
unevenSpecific Gravity
2.7Colors
white, gray, pale green, yellowish, brownishTransparency
translucentType Locality
Pietranera, Rovegno, Genova Province, Liguria, ItalyMineral Group
SilicatesUses
cosmetics, ceramics, paint filler, paper, carving stoneAssociated Minerals
serpentine, chlorite, dolomite, magnesite, tremoliteRarity
commonGeological Context
Talc is a metamorphic mineral formed from the alteration of magnesium-rich rocks such as serpentinites and dolomitic marbles under low-grade metamorphic conditions. It is a common product of hydrothermal alteration.
