Definition
Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster
History
Origin
Finland, Europe
Pennsylvania, U.S.
Discoverer
Jakob Sederholm
Unknown
Etymology
From Finnish Rapakivi which stands for crumbly rock
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