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Plagioclase (/ˈplædʒ(i)əˌkleɪs, ˈpleɪdʒ-, -ˌkleɪz/ PLAJ-(ee)-ə-klayss, PLAYJ-, -klayz) is a
series of
tectosilicate (framework silicate)
minerals within...
-
found to lack long
range order. The
lamellar separation only
occurs in
plagioclases of a
certain composition;
those of
calcic labradorite (50–70% anorthite)...
- pot****ium, or barium. The most
common members of the
feldspar group are the
plagioclase (sodium-calcium)
feldspars and the
alkali (pot****ium-sodium) feldspars...
- to 10
molecular percent of the
albite endmember). The
composition of
plagioclases is
often expressed as a
molar percentage of An%, or (for a
specific quantity)...
-
intrusive igneous rock
composed mostly of quartz,
alkali feldspar, and
plagioclase. It
forms from
magma with a high
content of
silica and
alkali metal oxides...
- phaneritic,
intrusive igneous rock
characterized by its composition:
mostly plagioclase feldspar (90–100%), with a
minimal mafic component (0–10%). Pyroxene...
-
rocks are
primarily composed of quartz,
plagioclase, and
alkali feldspar.
Granitoids range from
plagioclase-rich
tonalites to alkali-rich
syenites and...
- is
enriched in
alkali metal oxides.
Monzonite is
composed mostly of
plagioclase and
alkali feldspar.
Syenodiorite is an
obsolescent term for monzonite...
- and
plagioclase makes up more than 65% of the
total feldspar content.
Gabbroids are
distinguished from
dioritoids by an
anorthite (calcium
plagioclase) fraction...
-
quartz in
plagioclase. The
intergrowths are
microscopic in scale,
typically with
maximum dimensions less than 1 millimeter. The
plagioclase is sodium-rich...
