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 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.

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.

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.

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.

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. It is considered to be the extrusive counterpart of diorite, the plutonic equivalent.

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, 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 commonly erupts from stratovolcanoes, where they form small-volume flows that typically advance only short distances down the flanks of a volcano. The two examples shown here are short andesite flows advancing down the slope of the Lascar volcano in Chile, and the Colima volcano in Mexico.

The meaning of ANDESITE is an extrusive usually dark grayish rock consisting essentially of oligoclase or feldspar.