Talc — Talc
Talc Didier Descouens, Wikimedia Commons, CC BY SA 4.0

Mineral · Phyllosilicate

Talc

Mg3Si4O10(OH)2

Talc is hydrated magnesium silicate, hardness 1, the softest mineral on the Mohs scale and the substance of soapstone; crystals are rare, and specimens are massive greasy white, green or pink material from Vermont, Italy and China. Its soapy feel is diagnostic. Some talc deposits contain asbestiform tremolite, which is the reason for the talc-powder litigation.

FormulaMg3Si4O10(OH)2
IMA statusgrandfathered
Crystal systemTriclinic
Mohs hardness1
GroupPhyllosilicate
Type localityNone (known since antiquity)
StreakWhite
Specific gravity2.75
Reference listIMA List of Minerals (RRUFF) — verify formula and status against the current list

Handling and safety

Talc from unverified sources may contain asbestos fibres; avoid making dust.

Elsewhere

Cite this article

Stratum Study. "Talc" (Mineral). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/minerals/talc. Accessed 2026-09-20.

@misc{stratum-talc,
  title        = {Talc},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/minerals/talc}},
  year         = {2026},
  note         = {Mineral article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, wikidata, commons. Accessed 2026-09-20.}
}

Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.

Sources for this article: Stratum editorial (Stratum editorial);Wikidata (CC0);Wikimedia Commons (CC-BY-4.0). As of 2026-09-19; Study pack 2026.09. Data reproduced under the licences shown; text in Stratum's own words unless a section names its source.

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