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 …

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 …

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, …

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 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 …

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 …

Overview Andesite is a fine-grained extrusive igneous rock with intermediate composition between felsic and mafic. It is named after the Andes Mountains where it is common. Andesite forms from the …

Andesite is an extrusive rock intermediate in composition between rhyolite and basalt. Andesite lava is of moderate viscosity and forms thick lava flows and domes.