Definition
Jaspillite is an iron rich chemically formed rock which is common in banded iron formation rocks
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth
History
Origin
Western Australia, Minnesota
Ethiopia
Discoverer
Unknown
Obsius
Etymology
From Jaspilite (Mineral), a compact siliceous rock which resembles jasper
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Opaque Rock