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Igneous rock (igneous from Latin igneus 'fiery'), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava. The magma can be derived from partial melts of existing rocks in either a planet 's mantle or crust.
Claystone – Clastic sedimentary rock composed primarily of clay-sized particles. Coal – Combustible sedimentary rock composed primarily of carbon. Conglomerate – Sedimentary rock composed of smaller rock fragments. Coquina – Sedimentary rock that is composed mostly of fragments of shells.
Category. : Igneous rocks. Volcanoes portal. Igneous rocks include rocks that have solidified from a melt ( magma) either below the surface of a planet or natural satellite as intrusives or on the surface as extrusives or volcanic eruptions. Wikimedia Commons has media related to Igneous rocks.
Rhyolite (/ ˈraɪ.əlaɪt / RY-ə-lyte) [1][2][3][4] is the most silica -rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral assemblage is predominantly quartz, sanidine, and plagioclase.
Mineral assemblage of igneous rocks. Diorite (/ ˈdaɪ.əraɪt / DY-ə-ryte) [1][2] is an intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica and a relatively low content of alkali metals. It is intermediate in composition between low-silica (mafic) gabbro and high-silica ...
Igneous textures are used by geologists in determining the mode of origin of igneous rocks and are used in rock classification. The six main types of textures are phaneritic, aphanitic, porphyritic, glassy, pyroclastic, and pegmatitic. Aphanitic (a = not, phaner = visible) rocks, in contrast to phaneritic rocks, typically form from lava which ...
Gneiss (/ naɪs / nice) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. This rock is formed under pressures anywhere from 2 to 15 kbar, sometimes even more, and temperatures over 300°C (572°F).
This rock is a mixture of calcite, magnetite, and olivine. Carbonatite (/ kɑːrˈbɒnəˌtaɪt /) is a type of intrusive or extrusive igneous rock defined by mineralogic composition consisting of greater than 50% carbonate minerals. [1] Carbonatites may be confused with marble and may require geochemical verification.