Home > Rock Forming Minerals – June 20 > MS1359 Andalusite

Andalusite - Sold

Andalusite is an aluminosilicate, one of three common rock-forming polymorphs of Al2SiO5, along with kyanite and sillimanite. Delamétherie (1798) named andalusite after the Andalusia region of Spain.

At this locality in California, well formed andalusite crystals form in a pyrophyllite schist. Nearby the metamorphic grade was a bit higher, and kyanite has formed. This example still has some adhering pyrophyllite. Excellent teaching example. Complete.