Definition
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
History
Origin
Pennsylvania, U.S.
France
Discoverer
Unknown
Alexandre Brongniart
Etymology
From Greek anthrakites, from anthrax, anthrak meaning coal
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Family
Group
-
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock