Andesite

Carved andesite porphyry
MFA# 1980.73

Description

Andesite

A fine-grain, volcanic rock primarily containing andesine (a Plagioclase feldspar). Andesite may also contain smaller amounts of Biotite, Hornblende, and Pyroxene. Commonly found on the western coast of South America, andesite is named for the Andes mountains.

Resources and Citations

• Encyclopedia Britannica, http://www.britannica.com Comment: "andesite." Accessed 21 Jan. 2005 .

• Wikipedia: http://en.wikipedia.org/wiki/Andesite