Definition
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
Borolanite is a variety of Nepheline Syenite and belongs to igneous rocks and contains nepheline-alkali feldspar pseudomorphs which occur as conspicuous white spots in the dark rock matrix
History
Origin
Pennsylvania, U.S.
Scotland
Discoverer
Unknown
Unknown
Etymology
From Greek anthrakites, from anthrax, anthrak meaning coal
From Alkalic Igneous complex near Loch Borralan in northwest Scotland
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Plutonic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock