Gabbro: A Coarse-grained, Dark-Colored Plutonic Rock
Gabbro is a dense, coarse-grained, dark-colored, mostly plutonic rock. Its essential minerals are calcic plagioclase and pyroxene, but it may have minor amounts of amphibole,
Phaneritic
Kimberlite: A Rare, Brecciated Diamond Bearing Mantle Rock
Kimberlite is a potassic to ultrapotassic ultramafic rock with inequigranular texture. It is a rare type of peridotite with many xenoliths and xenocrysts, including, on
Peridotites: Dense, Coarse-Grained Ultramafic Intrusive Igneous Rocks
Peridotites are dense, coarse-grained, dark-colored ultramafic plutonic rocks with at least 40% olivine by volume. Members are dunite, kimberlite, harzburgite, wehrlite and lherzolite. Others are
A Detailed Guide into Nepheline Syenite Rocks
Nepheline syenite is a coarse-grained, pale-colored (white, gray, or pinkish) intrusive igneous rock that resembles granite. Its chemical composition is intermediate to felsic and has
Syenite: A Coarse-grained Granite-Like Plutonic Rock
Syenite is a coarse-grained, mostly light-colored intrusive rock with an intermediate to felsic composition. It has mainly alkali feldspar, lesser plagioclase, and one or more
Diorite: A Salt-and-Paper Looking Coarse-Grained Rock
Diorite is a coarse-grained, intermediate plutonic, or intrusive igneous rock. It has mainly plagioclase feldspar, biotite, hornblende, sometimes pyroxenes, and other minerals. This rock’s composition
Dunite: A Coarse-grained, Olivine-rich Greenish Plutonic Rock
Dunite is a coarse-grained, pale green to olive-green, ultramafic intrusive igneous rock with more than 90% olivine. It also may have smaller amounts of pyroxene,
Granite Pegmatites Texture Formation and Mineral Composition
Granite pegmatites are intrusive igneous rock with granitic composition and unusually large crystals, i.e., more than 0.4 inches (1 cm) with larger crystals more than 1.2 inches
Graphic Granite: A Unique Texture Resembling Ancient Cuneiform Writing
Graphic granite refers to granitic rocks with quartz-alkali feldspar intimate intergrowths whose texture or pattern resembles ancient cuneiform or runic writings or inscriptions. These rocks