
Andesite - Wikipedia
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. It has less than 20% quartz and 10% feldspathoid by volume, with at least 65% of the feldspar in the rock consisting of plagioclase.
Andesite: Igneous Rock - Pictures, Definition & More - Geology.com
Andesite is the name of a family of fine-grained, extrusive igneous rocks that are usually light to dark gray in color. They have a mineral composition that is intermediate between granite and basalt. Andesite is a rock typically found in volcanoes above convergent plate boundaries between continental and oceanic plates.
Andesite | Properties, Composition, Formation, Uses - Geology …
Sep 4, 2023 · Andesite is volcanic rock named after the Andes Mountains. Intermediate in silica content, it is usually gray in color and may be fine-grained or porphyritic. Andesite is the volcanic equivalent of diorite.
Everything You Ought to Know about Andesite Rock - Geology Base
Jul 3, 2023 · Andesite is a fine-grained, intermediate volcanic or extrusive igneous rock. Its composition lies between basalt and dacite, and it has mainly sodium-rich plagioclase and one or more mafic minerals, especially pyroxenes or hornblende.
Andesite: Identification, Pictures & Info for Rockhounds
Andesite is an extrusive igneous rock composed primarily of plagioclase feldspar and large amounts of mafic minerals like hornblende. It has an aphanitic texture, meaning its interlocking crystals cannot be seen by the naked eye. Andesite comes in many colors but is usually light or dark gray, and is often porphyritic.
Andesite - Simple English Wikipedia, the free encyclopedia
Andesite (/ˈændəzaɪt/) is a volcanic igneous rock with an intermediate composition. It is fine-grained (aphanitic) to porphyritic in texture, primarily composed of plagioclase feldspar (often andesine), along with pyroxene or hornblende.
Andesite - ALEX STREKEISEN
Andesite is recorded as being an important rock type associated with 422 of the 721 active volcanoes of the Earth; most of the modern Andesite occur above the Benioff seismic zone and the mean chemical composition of andesite is broadly similar to the estimated mean chemical composition of the continental crust of the Earth.
Andesite | Volcanic, Igneous, Magma | Britannica
andesite, any member of a large family of rocks that occur in most of the world’s volcanic areas. Andesites occur mainly as surface deposits and, to a lesser extent, as dikes and small plugs.
Andesite - Geology Hub
Andesite is a fine-grained volcanic rock (aphanitic texture) that forms through the rapid cooling of magma at the Earth’s surface. Its silica content ranges from 57-63%, placing it between the mafic and felsic rocks.
USGS: Volcano Hazards Program Glossary - Andesite
Andesite is a gray to black volcanic rock with between about 52 and 63 weight percent silica (SiO2). Andesites contain crystals composed primarily of plagioclase feldspar and one or more of the minerals pyroxene (clinopyroxene and orthopyroxene) and lesser amounts of hornblende.