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 …

What is Andesite? 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 …

Apr 11, 2018 · 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 …

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 …

It was named by Buch in 1826 from the Andes Mountains, South America. A dark-colored, fine-grained, mostly extrusive rock that is approximately the fine-grained equivalent of diorite.

Andesite is a fine-grained volcanic rock that forms through the rapid cooling of magma at or near the Earth's surface, typically in volcanic regions. It is an extrusive igneous rock, meaning it …

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.