Definition
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
History
Origin
Pennsylvania, U.S.
Germany
Discoverer
Unknown
Christian Leopold von Buch
Etymology
From Greek anthrakites, from anthrax, anthrak meaning coal
From Latin glaber bare, smooth, bald
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Family
Group
-
Plutonic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock