Definition
Origin
Discoverer
Etymology
Class
Sub-Class
Group
Other Categories
Luxullianite is a rare type of granite, known for presence of clusters of radially arranged acicular tourmaline crystals which are enclosed by phenocrysts of orthoclase and quartz in a matrix of quartz, tourmaline, alkali feldspar, brown mica.
From the village of Luxulyan in Cornwall, England, where this variety of granite is found
Coarse Grained Rock, Opaque Rock
Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition
From English feldspar and -ite
Durable Rock, Medium Hardness Rock
Fine Grained Rock, Opaque Rock