Luxullianite

Luxullianite from Cornwall, showing dark patches of tourmaline and pink crystals of orthoclase
Thin section of luxullianite from Cornwall, showing clusters of radially-arranged, acicular, greenish tourmaline crystals

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 orthoclase 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. An example may be seen in the Duke of Wellington's monument at St Paul's Cathedral in London.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.