POLISHED ANDALUSITE

Andalusite is a common metamorphic aluminum mesosilicate mineral, used along with its polymorphs kyanite and sillimanite (fibrolite) to determine temperature-pressure paths in metamorphic host rocks. The first specimens of andalusite were named in 1798 by Jean-Claude Delamétherie, and were believed to be from the southernmost state of Andalusia. However, the specimens were actually from the town of El Cardoso, in the Guadalajara region in central Spain: Delamétherie supposedly thought the town was in Andalusia.