Talc, or talcum, is a clay mineral made of hydrated magnesium silicate, Mg3Si4O10(OH)2. The Mohs scale takes the hardness of talc as its value 1, the softest mineral. It is a layered mineral with perfect basal cleavage, translucent to opaque, in colors from whitish gray to green, with a vitreous and pearly luster. Talc mostly forms by the metamorphism of magnesian minerals such as serpentine, pyroxene, amphibole and olivine in the presence of carbon dioxide and water, and it is common in metamorphic belts that contain ultramafic rocks. Soapstone is a metamorphic rock composed predominantly of talc. Ground talc is used as a lubricant and filler and in ceramics, paints, plastics, paper and cosmetics, including baby powder. China is the leading producer, with about 30 percent of world output in 2016.
Facts
Formation ClassSheet silicate (phyllosilicate), forming through the metamorphic hydration and alteration of magnesium-rich rocks such as peridotite, pyroxenite and dolomite. 1 Chemical Formula Hardness (Mohs) Classification
Strunz Class UseCeramic and Glass Manufacture 1 Connections
Associated With
The Mohs scale defines value 1 as the hardness of talc, the softest mineral.
Source Talc (Wikipedia)
Talc schist is a named schist variety defined by its talc content.
Source Schist (Wikipedia)
Talc is soapstone's dominant mineral constituent.
Source Soapstone (Wikipedia)
Caused By
Source EBSCO Research Starters: Metamorphic processes, rocks, and mineral deposits
Additional Source Talc (Wikipedia)Formation
Source Serpentinization (Wikipedia)
Classified As
In Discipline
Sources
1. Talc (Wikipedia)
Wikimedia FoundationLead section
Talc, or talcum, is a clay mineral composed of hydrated magnesium silicate, with the chemical formula Mg3Si4O10(OH)2.
Lead section
It is an ingredient in ceramics, paints, and roofing material.
Caused By: Metamorphism, Formation
Talc dominantly forms from the metamorphism of magnesian minerals such as serpentine, pyroxene, amphibole, and olivine, in the presence of carbon dioxide and water.
Caused By: Diagenesis, Formation
Talc is also found as a diagenetic mineral in sedimentary rocks
Caused By: Metasomatism, Formation
Talc can also be formed via a reaction between dolomite and silica, which is typical of skarnification of dolomites by silica-flooding in contact metamorphic aureoles
View the Source 2. minerals.net: Talc
minerals.netColor field
White, beige, gray, yellow, brown, pink, purple, blue, green. Rarely colorless.
Luster field
Greasy, waxy, pearly
About
as it is usually uninteresting and fairly common
View the Source Wikidata: Talc
Wikidata Q134583
Soapstone (Wikipedia)
Wikimedia FoundationAssociated With: Soapstone, Lead section, composition sentenceQuote, Associated With: Soapstone, Lead section, composition sentence
It is composed largely of the magnesium-rich mineral talc.
Schist (Wikipedia)
Wikimedia FoundationAssociated With: Schist, Body, protolith sectionQuote, Associated With: Schist, Body, protolith section
Talc schist also forms from metamorphosis of talc-bearing carbonate rocks formed by hydrothermal alteration.
EBSCO Research Starters: Metamorphic processes, rocks, and mineral deposits
EBSCO Research StartersCaused By: Metamorphism, Metamorphic mineral depositsQuote, Caused By: Metamorphism, Metamorphic mineral deposits
Talc forms by regional metamorphism at low to moderate temperatures and low to moderate pressures.
Serpentinization (Wikipedia)
Caused By: Serpentinization, LeadQuote, Caused By: Serpentinization, Lead
Minerals formed by serpentinization include the serpentine group minerals (antigorite, lizardite, chrysotile), brucite, talc, Ni-Fe alloys, and magnetite.
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