"Talcum" redirects here. For other uses, see Talcum (disambiguation) and TALC.
"Magnesium silicate" redirects here. For the synthetic form, see synthetic magnesium silicate. For the chemical and mineral with the [SiO4]−4 anion, see forsterite.
Hydrated magnesium phyllosilicate mineral
Talc
General
Category
Silicate mineral
Formula (repeating unit)
Mg3Si4O10(OH)2
IMA symbol
Tlc[1]
Strunz classification
9.EC.05
Crystal system
Monoclinic or triclinic[2]
Crystal class
Either prismatic (2m) or pinacoidal (1)[3]
Space group
C2/c or C1
Unit cell
a = 5.291 Å, b = 9.173 Å c = 5.290 Å; α = 98.68° β = 119.90°, γ = 90.09°; Z = 2 or a = 5.287 Å, b = 9.158 Å c = 18.95 [Å], β = 99.3°; Z = 4[3]
Identification
Color
Light to dark green, brown, white, grey, colorless
Crystal habit
Foliated to fibrous masses, rare as platey to pyramidal crystals
Cleavage
Perfect on {001} basal cleavage
Fracture
Flat surfaces (not cleavage), fracture in an uneven pattern
Talc, or talcum, is a clay mineral composed of hydrated magnesium silicate, with the chemical formula Mg3Si4O10(OH)2. Talc in powdered form, often combined with corn starch, is used as baby powder. This mineral is used as a thickening agent and lubricant. It is an ingredient in ceramics, paints, and roofing material. It is a main ingredient in many cosmetics.[6] It occurs as foliated to fibrous masses, and in an exceptionally rare crystal form. It has a perfect basal cleavage and an uneven flat fracture, and it is foliated with a two-dimensional platy form.
The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 1 as the hardness of talc, the softest mineral. When scraped on a streak plate, talc produces a white streak, though this indicator is of little importance, because most silicate minerals produce a white streak. Talc is translucent to opaque, with colors ranging from whitish grey to green with a vitreous and pearly luster. Talc is not soluble in water, and is slightly soluble in dilute mineral acids.[7]
Soapstone is a metamorphic rock composed predominantly of talc.
^Warr, L. N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
^W. A. Deer; R. A. Howie; J. Zussman, eds. (1992). An Introduction to the Rock-Forming Minerals (2nd ed.). Prentice Hall. ISBN 0-582-30094-0.
^ abcAnthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C., eds. (1995). "Talc" (PDF). Handbook of Mineralogy. Vol. II (Silica, Silicates). Chantilly, Virginia: Mineralogical Society of America. ISBN 0962209716.
^Talc, Mindat.org
^Talc Mineral Data, WebMineral.com
^"Talc". Minerals Education Coalition.
^Profiles of Drug Substances, Excipients and Related Methodology, Volume 36 ISBN 978-0-123-87667-6 p. 283
Talc, or talcum, is a clay mineral composed of hydrated magnesium silicate, with the chemical formula Mg3Si4O10(OH)2. Talc in powdered form, often combined...
Talc is a mineral composed of magnesium silicate. TALC may refer to: The American Lutheran Church, a Christian Protestant denomination in the United States...
steatite or soaprock) is a talc-schist, which is a type of metamorphic rock. It is composed largely of the magnesium-rich mineral talc. It is produced by dynamothermal...
Norwegian Talc AS is a manufacturer of talc located in Knarrevik in Fjell, Norway. It is owned by Omya. In 1989, the company, which at the time had plants...
all talc products to be asbestos-free, and today there is strict quality control in the production of talc products. Separating cosmetic-grade talc (e...
ultramafic rocks which have undergone talc-carbonation or carbonation reactions: talc and the carbonate mineral magnesite. Talc carbonate mineral assemblages...
February 13, 2019, the North American Talc Subsidiaries of Imerys (Imerys Talc America, Imerys Talc Vermont, Imerys Talc Canada) filed bankruptcy under Chapter...
caused by talc. It has been related to silicosis resulting from inhalation of talc and silicates. It is also tied to heroin use where talc might be used...
for preventing diaper rash and for cosmetic uses. It may be composed of talc (in which case it is also called talcum powder), corn starch or potato starch...
are often cut with cheap talc. Natural talc is cheap but contains asbestos while asbestos-free talc is more expensive. Talc that has asbestos is generally...
plates. This texture reflects a high content of platy minerals, such as mica, talc, chlorite, or graphite. These are often interleaved with more granular minerals...
often cut with cheap talc. Natural talc is cheap but contains asbestos while asbestos-free talc is more expensive. Inhaled talc that has asbestos is generally...
bleomycin, tetracycline (e.g., minocycline), povidone-iodine, or a slurry of talc can be introduced into the pleural space through a chest drain. The instilled...
meteorite impact Talc carbonate – A metamorphosed ultramafic rock with talc as an essential constituent; similar to a serpentinite Soapstone – Talc-bearing metamorphic...
example at Salau in the Ariège region of France. The major talc deposit is the Trimouns talc quarry, near Luzenac (Ariège), the largest in the world (400...
reactions favor formation of talc, magnesite (magnesium carbonate), and tremolite amphibole. These are classed as talc-carbonation reactions. Below XCO2...
April 30, 2023. "Women's health concerns prompt condom makers to stop using talc". The Free Lance-Star. January 11, 1996. p. D3. Retrieved May 14, 2016 –...
its kind in Austria since 1945. Lassing is the largest known carbonated talc deposit in the Eastern Alps. Geologically, it is part of the northern greywacke...
rocks along with serpentinite. Anthophyllite is formed by the breakdown of talc in ultramafic rocks in the presence of water and carbon dioxide as a prograde...
and commonly includes two or more of the following minerals: serpentine, talc, sepiolite, smectite, or chlorite, and Ni-Mg silicates, with or without alumina...
a contaminant in vermiculite, chrysotile (itself a type of asbestos) and talc. Tremolite is an indicator of metamorphic grade since at high temperatures...
Canada, talc-like bright white appearance, high grade, no impurities; 21 million ton deposit. Russia – pale green foliated masses, very like talc in appearance...
caused by drug abuse include maculopathy, Saturday night retinopathy, and talc retinopathy. Common symptoms include temporary and permanent vision loss...
a lawsuit by Merck & Co’s seeking to hold Bayer AG responsible for more talc-related liabilities stemming from its $14.2 billion purchase of Merck’s consumer...
T-O-T) is often referred to as a talc layer, since talc is composed entirely of stacked TOT layers. The TOT layers of talc are electrically neutral and are...
The Talc City Hills is a mountain range in the northern Mojave Desert, in Inyo County, California. They are just north of California State Route 190 west...
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