Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
History
Origin
North America
-
Discoverer
Ferdinand von Richthofen
Johann Gottlob Lehmann
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,
Class
Igneous Rocks
Sedimentary 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