- The
feldspathoids are a
group of
tectosilicate minerals which resemble feldspars but have a
different structure and much
lower silica content. They occur...
-
gabbro contains up to 10%
feldspathoids rather than quartz. "Foid" in the name is
usually replaced by the
specific feldspathoid that is most
abundant in...
-
component of
lapis lazuli is
lazurite (25% to 40%),[citation needed] a blue
feldspathoid silicate mineral of the
sodalite family, with the
formula Na7Ca(Al6Si6O24)(SO4)(S3)...
- at
least 10% of the
mineral content consists of quartz, feldspar, or
feldspathoid minerals,
classification begins with the QAPF diagram. The
relative abundances...
-
essential alkali feldspar.
Relatively minor plagioclase and
quartz or a
feldspathoid such as
nepheline may also be present. This is
reflected in the position...
-
Ancient Gr**** νεφέλη (nephélē) 'cloud'), is a rock-forming
mineral in the
feldspathoid group – a silica-undersaturated aluminosilicate, Na3KAl4Si4O16, that...
- BaAl2Si2O8
Hyalophane – (K,Ba)[Al(Si,Al)Si2O8]
Rubicline – (RbAlSi3O8
Feldspathoid group Cancrinite subgroup Cancrinite – (Na,Ca,◻)8(Al6Si6O24)(CO3,SO4)2·2H2O...
- The
acronym QAPF
stands for "quartz,
alkali feldspar, plagioclase,
feldspathoid (foid)",
which are the four
mineral groups used for
classification in...
-
olivine Es****ite –
Igneous rock type Foidolite –
Igneous rock rich in
feldspathoid minerals Gabbro – Co****-grained
mafic intrusive rock Granite – Type...
- quartz, feldspars, or
feldspathoids.
classification is
based on the
percentages of quartz,
alkali feldspar, plagioclase, and
feldspathoid out of the total...
