Definition
Gritstone or grit is a hard, coarse-grained, siliceous sandstone
Appinite is an igneous rock in which the crystals are so fine grained that individual minerals cannot be easily distinguished
History
Origin
Pennines, England
-
Discoverer
J.J. Ferber
Unknown
Etymology
From Grit + Stone
From the variety of Lamprophyre Greek lampros bright and shining + porphureos purple
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Plutonic
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Opaque Rock