Definition
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
Eclogite is an extreme metamorphic rock, formed by regional metamorphism of basalt rock under very high pressure and temperature
History
Origin
Ethiopia
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Discoverer
Obsius
René Just Haüy
Etymology
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
From French, Greek eklogē selection with reference to the selective content of the rock + -ite1
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
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Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock