Definition
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
History
Origin
-
USA
Discoverer
Unknown
Unknown
Etymology
From French schiste, Greek skhistos i.e. split
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock