Luxulianite

Luxullianite (also Luxulyanite, Luxulianite) is a rare type of granite, notable for the presence of clusters of radially arranged acicular tourmaline crystals enclosed by phenocrysts of orthociase and quartz in a matrix of quartz, tourmaline, alkali feldspar, brown mica, and cassiterite.

The name originates from the village of Luxulyan in Cornwall, England, where this type of granite is found.