Definition
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities
History
Origin
-
-
Discoverer
Unknown
Unknown
Etymology
From French schiste, Greek skhistos i.e. split
From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung
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