Definition
Websterite is ultramafic and ultrabasic rock that consists of roughly equal proportions of orthopyroxene and clinopyroxene. It is a special type of pyroxenite.
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
History
Origin
Webster, North Carolina
Pennsylvania, U.S.
Discoverer
Unknown
Unknown
Etymology
From the town of Webster located in North Carolina
From Greek anthrakites, from anthrax, anthrak meaning coal
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Family
Group
Plutonic
-
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock