-
Oligoclase is a rock-forming
mineral belonging to the
plagioclase feldspars. In
chemical composition and in its
crystallographic and
physical characters...
- Gotthard.[better source needed] A
solid solution of the
plagioclase feldspar oligoclase +/− the pot****ium
feldspar orthoclase also
produces moonstone specimens...
-
Sunstone is a
microcline or
oligoclase feldspar,
which when
viewed from
certain directions exhibits a
spangled appearance. It has been
found in Southern...
-
silica and
related volcanics such as andesite.
Oligoclase is
common in
granite and monzonite. The name
oligoclase is
derived from the Gr**** olígos ('small,...
-
variety of
tonalite in
which the
plagioclase is
mostly in the form of
oligoclase.
Trondhjemites that
occur in the
oceanic crust or in
ophiolites are usually...
- (/ˈmʌɡiəraɪt/) is a type of
oligoclase-bearing basalt,
comprising olivine, apatite, and
opaque oxides. The main
feldspar in
mugearite is
oligoclase.
Mugearite is a...
-
Osumilite Otavite Ottrelite Otwayite Varieties that are not
valid species:
Oligoclase (a
mixture of
albite and anorthite) Onyx (a
monochromatic banded variety...
-
follows (with
percent anorthite in parentheses):
albite (0 to 10) NaAlSi3O8
oligoclase (10 to 30) (Na,Ca)(Al,Si)AlSi2O8
andesine (30 to 50)
NaAlSi 3O 8 – CaAl...
-
biotite (sp. gr. 3.1),
muscovite (sp. gr. 2.85),
quartz (sp. gr. 2.65),
oligoclase (sp. gr. 2.64), and
orthoclase (sp. gr. 2.56), the
crushed minerals float...
- with
phaneritic texture.
Feldspar is
present as
plagioclase (typically
oligoclase or andesine) with 10% or less pot****ium feldspar.
Quartz is
present at...
