Definition
Appinite is an igneous rock in which the crystals are so fine grained that individual minerals cannot be easily distinguished
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
History
Origin
-
France
Discoverer
Unknown
Alexandre Brongniart
Etymology
From the variety of Lamprophyre Greek lampros bright and shining + porphureos purple
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock