Definition
Dolomite is a sedimentary rock containing more than 50 percent of the mineral dolomite by weight
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
Southern Alps, France
Ethiopia
Discoverer
Dolomieu
Obsius
Etymology
From French, from the name of Dolomieu (1750–1801), the French geologist who discovered the rock
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Sedimentary 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
Opaque Rock