margarite

mineral

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Last updated

June 11, 2026

Quick Summary

The term "margarite" can refer to two distinct subjects. In mineralogy, margarite is a type of brittle mica. Brittle micas are silicate minerals that contain calcium, which increases their hardness, causing them to break rather than bend. Margarite and clintonite are examples of brittle micas, found in metamorphic rocks.1

Archaically, "margarite" also means pearl, derived from Greek and Latin roots. This older meaning is distinct from its mineralogical definition.2

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brittle mica
Margarite and clintonite are examples of brittle micas. Both of these minerals occur in metamorphic rocks such as pelitic schists and metasomatized marbles as well as metamorphosed bauxites, basalts, and anorthosites.
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Margarite and clintonite are examples of brittle micas. Both of these minerals occur in metamorphic rocks such as pelitic schists and metasomatized marbles as well as metamorphosed bauxites, basalts, and anorthosites.
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clintonite
…group of micas (also including margarite) in which calcium substitutes for potassium and the silicon content increases. The members of the clintonite group, also called the brittle micas, are harder and more brittle than the common micas. For chemical formula and detailed physical properties, see mica (table).
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…group of micas (also including margarite) in which calcium substitutes for potassium and the silicon content increases. The members of the clintonite group, also called the brittle micas, are harder and more brittle than the common micas. For chemical formula and detailed physical properties, see mica (table).
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