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Biotite is a
common group of
phyllosilicate minerals within the mica group, with the
approximate chemical formula K(Mg,Fe)3AlSi3O10(F,OH)2. It is primarily...
- not as
useful for
rocks in
other facies with
higher Ca-garnets and
mixed biotites.
Several calibrations have been
completed that take into
account the non-ideal...
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somewhat equigranular matrix of
feldspar and
quartz with
scattered darker biotite mica and
amphibole (often hornblende)
peppering the
lighter color minerals...
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minor amounts of
muscovite mica as the
lighter colored mineral components.
Biotite and
amphiboles often in the form of
hornblende are more
abundant in granodiorite...
- also be
named after a
characteristic component such as
garnet gneiss,
biotite gneiss,
albite gneiss, and so forth.
Orthogneiss designates a
gneiss derived...
-
known as
magnesium mica.
Phlogopite is the
magnesium endmember of the
biotite solid solution series, with the
chemical formula KMg3AlSi3O10(F,OH)2. Iron...
- effect.
Vermiculite forms by the
weathering or
hydrothermal alteration of
biotite or phlogopite.
Large commercial vermiculite mines exist in the
United States...
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Formation consists chiefly of
biotite-quartz
phyllite and chlorite-
biotite phyllite intercalated with
minor amounts of
biotite-sericite-quartz schist. Between...
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Retrieved 2019-02-26. Pinson, W. H., Jr., et al., K-Ar and Rb-Sr Ages of
Biotites from Colombia,
South America,
Geological Society of
America Bulletin 1962...
- (rhyolites).
Dacite consists mostly of
plagioclase feldspar and
quartz with
biotite, hornblende, and
pyroxene (augite or enstatite). The
quartz appears as...
