mineral

Mica (Biotite or Phlogopite variety)

Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)

AI-generated identification · may be incorrect

Hardness: 2.5–3.0 on Mohs scale; Color: Bronze-gold, brown, or amber; Luster: Pearly to submetallic; Crystal Structure: Monoclinic; Cleavage: Perfect basal cleavage (easily peels into thin, flexible sheets); Specific Gravity: 2.7–3.3.

Hardness: 2
Color: Bronze-gold, brown, or amber
Luster: Pearly to submetallic

Identified March 16, 2026More mineral →

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Physical properties

Formation & geological history

Formed through metamorphic or igneous processes. It is common in pegmatites, schists, and gniesses, typically forming in volcanic environments or at high-pressure metamorphic zones. Can range from hundreds of millions to billions of years old depending on the host rock.

Uses & applications

Used widely in industry as an electrical insulator, in cosmetics (mica shimmer), as a filler in plastics or rubber, and in specialized high-temperature windows for furnaces or kilns.

Geological facts

Mica is famous for its 'books' (large crystals) and was historically used as a glass substitute for lanterns and windows in Russia, earning its name 'Muscovy-glass'. It is highly heat resistant and does not conduct electricity.

Field identification & locations

Identify in the field by its distinct ability to flake apart into paper-thin, transparent, or semi-opaque flexible sheets. It feels slightly greasy or soapy and shows a brilliant 'sparkle' under sunlight. Commonly found in granite outcrops or riverbeds near metamorphic terrain.