- 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...
- at
least 10% of the
mineral content consists of quartz, feldspar, or
feldspathoid minerals,
classification begins with the QAPF diagram. The
relative abundances...
-
quartz (crystalline
silica (SiO2)),
alkali feldspar, plagioclase, and
feldspathoid (QAPF) are
particularly important. An
aphanitic (fine-grained) igneous...
-
olivine Es****ite –
Igneous rock type Foidolite –
Igneous rock rich in
feldspathoid minerals Gabbro – Co****-grained
mafic intrusive rock Granite – Type...
- The
acronym QAPF
stands for "Quartz,
Alkali feldspar, Plagioclase,
Feldspathoid (Foid)",
which are the four
mineral groups used for
classification in...
-
chloride with
formula (Na,Ca)8[(S,Cl,SO4,OH)2|(Al6Si6O24)]. It is a
feldspathoid and a
member of the
sodalite group.
Lazurite crystallizes in the isometric...
- may
refer to:
Firearm Owner's Identification, a FOID card in
Illinois Feldspathoid,
sometimes called a "foid", a
class of
mineral found in
igneous rocks...
-
Ancient Gr**** νεφέλη (nephélē) 'cloud'), is a rock-forming
mineral in the
feldspathoid group – a silica-undersaturated aluminosilicate, Na3KAl4Si4O16, that...
-
essential alkali feldspar.
Relatively minor plagioclase and
quartz or a
feldspathoid such as
nepheline may also be present. This is
reflected in the position...
