Muscovite — Muscovite
Muscovite Wikimedia Commons contributor, Wikimedia Commons, CC BY 2.0

Mineral · Mica group

Muscovite

KAl2(AlSi3O10)(OH)2

Muscovite is white mica, the flexible, elastic, perfectly cleavable sheet silicate of granites and pegmatites, sold as 'books' from Minas Gerais and Pakistan, star mica from Brazil and the matrix under Pakistani aquamarine. It is cheap and a good teaching mineral for cleavage. Fuchsite is its green chromium variety.

FormulaKAl2(AlSi3O10)(OH)2
IMA statusgrandfathered
Crystal systemMonoclinic
Mohs hardness2–2.5
GroupMica group
Type localityNone (Muscovy, historical)
StreakWhite
Specific gravity2.8
Reference listIMA List of Minerals (RRUFF) — verify formula and status against the current list

Elsewhere

Cite this article

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

@misc{stratum-muscovite,
  title        = {Muscovite},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/minerals/muscovite}},
  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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