Definition
Gritstone or grit is a hard, coarse-grained, siliceous sandstone
Lamprophyre is uncommon igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks and small intrusions
History
Origin
Pennines, England
-
Discoverer
J.J. Ferber
Unknown
Etymology
From Grit + Stone
From 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