Definition
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.
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
History
Origin
England
-
Discoverer
Unknown
Unknown
Etymology
From the village of Luxulyan in Cornwall, England, where this variety of granite is found
From English feldspar and -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Plutonic
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock