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 …

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 between …

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.

Jul 3, 2023 · Andesite is a durable, hard rock with a Mohs hardness of 6-7 and high compressive strength, making it ideal for various uses. Some uses of andesite rocks include building stones, …

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 volcanic …

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 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 …