A group of sheet silicate minerals that split into thin, flexible, glittering layers. It is the flecked shine in granite and gneiss, and the third of the three common minerals, with quartz and feldspar, that give granite its speckled texture. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/
Facts
Classification
Crystal System Classification UseIndustrial and Abrasive 2 Wikipedia 'Mica' states this use (or use-bearing statement); earth5 pass. Formation ClassSheet silicate (phyllosilicate) 3 Chemical FormulaX2Y4-6Z8O20(OH,F)4 (general mica-group formula) 1 Hardness (Mohs) Connections
Associated With
Granite's own lead description names mica as one of its main constituent minerals.
Source Granite (Wikipedia)
Mica named as one of the three dominant minerals of most pegmatites.
Source Pegmatite (Wikipedia)
Mica-rich schist (mica schist) is one of the most common schist varieties.
Source Schist (Wikipedia)
Classified As
Crystallizes In System
In Discipline
Source Mineral (Wikipedia)
Sources
1. Mica (Wikipedia)
Wikimedia FoundationClassification section
Chemically, micas can be given the general formula X2Y4-6Z8O20(OH, F)4, in which X is K, Na, or Ca or less commonly Ba, Rb, or Cs; Y is Al, Mg, or Fe or less commonly Mn, Cr, Ti, Li, etc.; Z is chiefly Si or Al, but also may include Fe3+ or Ti.
Lead section
Micas () are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into fragile elastic plates.
Mica (Wikipedia), body text
All crystallize in the monoclinic system, with a tendency towards pseudohexagonal crystals
View the Source 2. Wikidata: Mica
Wikidata Q114675
3. Mineral (Wikipedia)
Wikimedia FoundationLead sectionQuote, Lead section
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.
Granite (Wikipedia)
Wikimedia FoundationAssociated With: Granite, Lead sectionQuote, Associated With: Granite, Lead section
is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, mica and plagioclase.
Pegmatite (Wikipedia)
Wikimedia FoundationAssociated With: Pegmatite, Lead sectionQuote, Associated With: Pegmatite, Lead section
Most pegmatites are composed of quartz, feldspar, and mica, having a similar silicic composition to granite.
Schist (Wikipedia)
Wikimedia FoundationAssociated With: Schist, Body, protolith sectionQuote, Associated With: Schist, Body, protolith section
Schist metamorphosed from mudstone is particularly common and is often very rich in mica (a mica schist).
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