Plutonic rocks

Granite (, ) is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, mica and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underground. It is common in the continental crust of Earth, where it is found in igneous intrusions. These range in size from dikes only a few centimeters across to batholiths exposed over hundreds of square kilometers.

thumb|Gabbro specimen from Duluth, Minnesota thumb|Photomicrograph of a [[thin section of gabbro]]

thumb|Diorite thumb|Orbicular diorite from Corsica (corsite) thumb|upright=1.7|QAPF diagram with dioritoid fields highlighted in yellow and diorite in red thumb|upright=1.4|Mineral assemblage of igneous rocks

thumb|upright=1.4|A sample of granodiorite from the Massif Central, France thumb|upright=1.4|QAPF diagram for classification of plutonic rocks. The composition field for granodiorite is indicated in blue. upright=1.4|thumb|Mineral assemblage of igneous rocks thumb|Photomicrograph of [[thin section of granodiorite from Slovakia (in crossed polarised light)]]

Peridotite ( ) is a dense, phaneritic (coarse-grained) igneous rock consisting mostly of the silicate minerals olivine and pyroxene. Peridotite is ultramafic, as the rock contains less than 45% silica. It is high in magnesium (Mg2+), reflecting the high proportions of magnesium-rich olivine, with appreciable iron. Peridotite is derived from Earth's mantle, either as solid blocks and fragments, or as crystals accumulated from magmas that formed in the mantle. The compositions of peridotites from these layered igneous complexes vary widely, reflecting the relative proportions of pyroxenes, chrom

sheet of rock formed in a fracture in a pre-existing rock body

thumb|right|Aplite dyke cutting Sentinel granodiorite on [[Sentinel Dome]] right|thumb|Aplite, showing fine-grained texture Aplite () is an intrusive igneous rock that has a granitic composition. Aplites are fine-grained to aphanitic (without grains visible to the naked eye) and may consist of only quartz and feldspar or the term may refer to any leucocratic (pale-coloured) minor intrusion of that grain size. They are associated with the later stages of many larger intermediate to felsic intrusions.

thumb|Ptygmatic folding in migmatite on Naissaar Island, Estonia thumb|Migmatite on the coast of Saaremaa, Estonia thumb|Intricately-folded migmatite from near Geirangerfjord, Norway

Anorthosite () is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal mafic component (0–10%). Pyroxene, ilmenite, magnetite, and olivine are the mafic minerals most commonly present.

thumb|right|upright=1.2|Small volcanic bomb of (black) [[basanite with (green) dunite]]

holocrystalline plutonic rock

thumb|Pyroxenite from Rustenburg, South Africa Pyroxenite is an ultramafic igneous rock consisting essentially of minerals of the pyroxene group, such as augite, diopside, hypersthene, bronzite or enstatite. Pyroxenes have the general formula , where X represents ions of calcium (Ca), sodium (Na), iron (Fe(II)) or magnesium (Mg) and more rarely zinc, manganese or lithium, and Y represents ions of smaller size, such as chromium (Cr), aluminium (Al), magnesium (Mg), cobalt (Co), manganese (Mn), scandium (Sc), titanium (Ti), vanadium (V) or even iron (Fe(II) or Fe(III)). Pyroxenes share a common

body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth

thumb|300px|Hornblendite from Poland

thumb|A larvikite quarry in Larvik, Norway, 2008 thumb|Polished larvikite (marketed as "Blue Pearl Granite"), showing labradorescence, is a popular decorative stone. thumb|Light larvikite with a polished surface

igneous rocks formed by the accumulation of crystals from a magma either by settling or floating.

thumb|A quarry of listwanite in the region of [[Aosta Valley, in Italy]] thumb|upright|A quarry of listwanite in the region of Aosta Valley, in Italy Listwanite (also sometimes spelled listvenite, listvanite, or listwaenite) is a rock type that forms when the groundmass of ultramafic rocks, most commonly mantle peridotites, is partially altered to carbonate minerals and cut by ubiquitous carbonate veins containing one or more of magnesite, calcite, dolomite, ankerite, and/or siderite. Original pyroxene and olivine in the peridotite are commonly altered to Mg- or Ca-carbonate and hydrous Mg-sil

thumb|Ijolite (Oka Carbonatite Complex, Early Cretaceous, 124-125 Ma; Oka Niobium Mine, Quebec, Canada) Ijolite is an igneous rock consisting essentially of nepheline and augite. Ijolite is a rare rock type of considerable importance from a mineralogical and petrological standpoint. The word is derived from the first syllable of the Finnish words such as Iivaara, Iijoki and Ii, all geographical names in Finland, and the Ancient Greek Xiflos, a stone. Ijolite occurs in various parts of the Kainuu region of eastern Finland and in the Kola Peninsula of northwest Russia on the shores of the White

thumb|upright=1.2|Craigleith, an island in Scotland, composed of essexite

Shonkinite is an intrusive igneous rock found in few places in the world. It is unique in having low silica, feldspathoid minerals, and large blocky crystals of black augite. It makes up much of the hard dark grey rock comprising certain mountains and buttes in Montana that are remnants of laccoliths and stocks, such as the Highwood mountains.

thumb|Enderbite from Vinnytsia Oblast, [[Ukraine]] In geology, enderbite is an igneous rock of the charnockite series, consisting essentially of quartz, antiperthite (or perthite), orthopyroxene (usually hypersthene) and magnetite, and is equivalent to an orthopyroxene bearing tonalite. It is named for its occurrence in Enderby Land, Antarctica.

Monzodiorite is an intrusive rock with a composition intermediate between diorite and monzonite. It is defined in the QAPF classification as coarse-grained igneous rock in which quartz makes up 0% to 5% of the QAPF mineral fraction, plagioclase makes up 65% to 90% of the total feldspar content, and the plagioclase is sodium-rich (%An < 50).

thumb|Websterite highlighted in a ternary diagram thumb|Cumulate rock|Cumulate layers of websterite in the [[McMurdo Dry Valleys in Antarctica]]

Syenogranite is a fine to coarse grained intrusive rock of the same general composition as granite. For example, the syenogranite in the Salmon Mountains in Idaho is pink to tan and composed of 45–55% alkali feldspar, 15–20% plagioclase, 15–20% quartz, 5–8% biotite, 3–5% hornblende, and accessory magnetite (Evans and Green, 2003).

Mangerite is a plutonic intrusive igneous rock, that is essentially a hypersthene-bearing monzonite. It often occurs in association with norite, anorthosite, charnockite and rapakivi granite in Proterozoic metamorphic belts. It is characterised by the presence of mesoperthite. It was named for Manger, Norway, by Carl Fredrik Kolderup in 1903.

thumb|right|Specimen of cumberlandite on display at the Roger Williams Park Museum of Natural History and Planetarium. Specimen is approximately 1 foot (30 cm) wide. Cumberlandite is a specific type of plutonic rock called a melanocratic troctolite, or melatroctolite. It is the state rock of Rhode Island and can be found in a lot in Cumberland, Rhode Island at Iron Mine Hill. Further traces can be found scattered throughout the Narragansett Bay watershed as far as Martha's Vineyard and Block Island. Cumberlandite is not exclusive to Rhode Island; it is also found in Taberg, Sweden. It is sligh

thumb|Chromitite with bronzite [[phenocrysts from Stillwater Igneous Complex]] Chromitite is an igneous cumulate rock composed mostly of the mineral chromite. It is found in layered intrusions such as the Bushveld Igneous Complex in South Africa, the Stillwater igneous complex in Montana and the Ring of Fire discovery in Ontario.

Monzogabbro is an intrusive rock with a composition intermediate between gabbro and monzonite. It is defined in the QAPF classification as coarse-grained igneous rock in which quartz makes up 0% to 5% of the QAPF mineral fraction, plagioclase makes up 65% to 90% of the total feldspar content, and the plagioclase is calcium-rich (%An > 50).