Quartz diorite
Encyclopedia
Quartz diorite is an igneous, plutonic (intrusive) rock
, of felsic
composition, with phaneritic
texture. Feldspar
is present as plagioclase
(typically oligoclase
or andesine
) with 10% or less potassium feldspar. Quartz
is present at between 5 to 20% of the rock. Biotite
, amphibole
s and pyroxene
s are common dark accessory minerals.
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
, of felsic
Felsic
The word "felsic" is a term used in geology to refer to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium....
composition, with phaneritic
Phanerite
A phanerite is an igneous rock having the grains of its essential minerals large enough to be seen macroscopically, i.e. are distinguishable with the unaided eye. Synonymous with coarse grained or megascopically crystalline.Cf: aphanitic....
texture. Feldspar
Feldspar
Feldspars are a group of rock-forming tectosilicate minerals which make up as much as 60% of the Earth's crust....
is present as plagioclase
Plagioclase
Plagioclase is an important series of tectosilicate minerals within the feldspar family. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a solid solution series, more properly known as the plagioclase feldspar series...
(typically oligoclase
Oligoclase
Oligoclase is a rock-forming mineral belonging to the plagioclase feldspars. In chemical composition and in its crystallographic and physical characters it is intermediate between albite and anorthite . The albite:anorthite molar ratio ranges from 90:10 to 70:30.Oligoclase is a high sodium...
or andesine
Andesine
Andesine is a silicate mineral, a member of the plagioclase feldspar solid solution series. Its chemical formula is 4O8, where Ca/ is between 30%-50%...
) with 10% or less potassium feldspar. Quartz
Quartz
Quartz is the second-most-abundant mineral in the Earth's continental crust, after feldspar. It is made up of a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall formula SiO2. There are many different varieties of quartz,...
is present at between 5 to 20% of the rock. Biotite
Biotite
Biotite is a common phyllosilicate mineral within the mica group, with the approximate chemical formula . More generally, it refers to the dark mica series, primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more aluminous endmembers...
, amphibole
Amphibole
Amphibole is the name of an important group of generally dark-colored rock-forming inosilicate minerals, composed of double chain tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures.-Mineralogy:...
s and pyroxene
Pyroxene
The pyroxenes are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. They share a common structure consisting of single chains of silica tetrahedra and they crystallize in the monoclinic and orthorhombic systems...
s are common dark accessory minerals.