A member of the 2:1 phyllosilicates
(sheet silicates) with composition Mg6
; sp. gr. 2.58–2.83; hardness
1 (it has the lowest hardness on Mohs
's scale of hardness); monoclinic
; rare crystals are tabular
, often massive
; white to green; cleavage
; massive talc (soapstone or steatite) can be formed during the low-grade metamorphism
of siliceous dolomites
; and as a secondary mineral
during hydrothermal alteration
of ultrabasic igneous
rocks along shear planes. It is associated with serpentization
changing to talc and magnetite
by addition of CO2
. It is used extensively as a mineral filler.
a white, gray, or pale green soft mineral with a greasy feel, occurring as translucent masses or laminae and consisting of magnesium hydroxyl silicate.
(talced, talc·ing) [tr.]
powder or treat (something) with talc.
/ ˈtalkōs/ adj. ( Geol. ).
/ ˈtalkē/ adj.
talc (hydrous magnesium silicate, Mg3Si4O10(OH)2).
It occurs as rare tabulate crystals in a monoclinic system and as masses. It is used as base for talcum powder and in ceramics. Hardness 1; r.d. 2.6.
, ilk, milk, silk
•Liebfraumilch • buttermilk • volk
, hulk, skulk, sulk
species of translucent or shining minerals, e.g. mica. XVI. — F. talc
or medL. talcum
XVI) — Arab. ṭalḳ
— Pers. talk
talc (tal'k) n.
a soft white powder consisting of magnesium silicate, used as a dusting powder.