Definition
Gritstone or grit is a hard, coarse-grained, siliceous sandstone
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
History
Origin
Pennines, England
-
Discoverer
J.J. Ferber
Unknown
Etymology
From Grit + Stone
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock