Igneous rock (igneous from Latin igneus 'fiery'), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic...

ways igneous rock can form. The other is extrusion, such as a volcanic eruption or similar event. An intrusion is any body of intrusive igneous rock, formed...

metamorphic rock, and sedimentary rock. Adakite – Volcanic rock type Andesite – Type of volcanic rock Alkali feldspar granite – Type of igneous rock rich in...

classifying igneous rock. The content of alkali metal oxides is next in importance. About 65% of the Earth's crust by volume consists of igneous rocks. Of...

In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly...

metamorphic, and igneous. Each rock type is altered when it is forced out of its equilibrium conditions. For example, an igneous rock such as basalt may...

is a highly vesicular rock produced in explosive volcanic eruptions.[citation needed] Most modern petrologists classify igneous rocks, including volcanic...

ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally...

name was given to any igneous rocks with large crystals. The adjective porphyritic now refers to a certain texture of igneous rock regardless of its chemical...

Granite (/ˈɡrænɪt/ GRAN-it) is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms...

erupted as pyroclastic rock than as lava flows. Rhyolitic ash-flow tuffs are among the most voluminous of continental igneous rock formations. Rhyolitic...

US: /bəˈsɔːlt, ˈbeɪsɔːlt/) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium...

mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic...

Igneous textures include the rock textures occurring in igneous rocks. Igneous textures are used by geologists in determining the mode of origin of igneous...

Gabbro (/ˈɡæb.roʊ/) is a phaneritic (coarse-grained), mafic intrusive igneous rock formed from the slow cooling of magnesium-rich and iron-rich magma into...

country rock is used include: When describing a pluton or dike, the igneous rock can be described as intruding the surrounding country rock, the rock into...

A subvolcanic rock, also known as a hypabyssal rock, is an intrusive igneous rock that is emplaced at depths less than 2 km (1.2 mi) within the crust...

coarse-grained igneous rock consisting mostly of the silicate minerals olivine and pyroxene. Peridotite is ultramafic, as the rock contains less than...

Trap rock, also known as either trapp or trap, is any dark-colored, fine-grained, non-granitic intrusive or extrusive igneous rock. Types of trap rock include...

Andesite is an aphanitic (fine-grained) to porphyritic (coarse-grained) igneous rock that is intermediate in its content of silica and low in alkali metals...

the rock remains mostly in the solid state, but gradually recrystallizes to a new texture or mineral composition. The protolith may be an igneous, sedimentary...

Ancient Greek bathos 'depth', and lithos 'rock') is a large mass of intrusive igneous rock (also called plutonic rock), larger than 100 km2 (40 sq mi) in area...

(/ˈdaɪ.əraɪt/ DY-ə-ryte) is an intrusive igneous rock formed by the slow cooling underground of magma (molten rock) that has a moderate content of silica...

Anorthosite (/əˈnɔːrθəsaɪt/) is a phaneritic, intrusive igneous rock characterized by its composition: mostly plagioclase feldspar (90–100%), with a minimal...

Kimberlite, an igneous rock and a rare variant of peridotite, is most commonly known to be the main host matrix for diamonds. It is named after the town...

Syenite is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at...

A pegmatite is an igneous rock showing a very coarse texture, with large interlocking crystals usually greater in size than 1 cm (0.4 in) and sometimes...

Larvikite is an igneous rock, specifically a variety of monzonite, notable for the presence of thumbnail-sized crystals of feldspar. These feldspars are...

Acidic rock or acid rock refers to the chemical composition of igneous rocks that has 63% wt% SiO2 content. Rocks described as acidic usually contain...

extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Obsidian is produced from felsic lava, rich in the lighter elements...