Chiastolite is a brown variety of andalusite which contains a black cross. The name chiastolite derives from the Greek chiastos meaning "cross marked". It is named for Andalusia where it was once found, in Spain. The mineral chiastolite is a variety of andalusite with the chemical composition Al₂SiO₅. It is noted for distinctive cross-shaped black inclusions of graphite. In areas around Georgetown, California, metamorphosed sediments contained andalusite and chiastolite in a graphite rich metasediment. Andalusite is called Lapis Crucifer in ancient texts, and has been used since ancient times for protection.