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Greywacke and Obsidian Definition


Obsidian and Greywacke Definition


Definition

Definition
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay  
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
-  
Ethiopia  

Discoverer
Unknown  
Obsius  

Etymology
From German Grauwacke, from grau grey + wacke  
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius  

Class
Sedimentary Rocks  
Igneous Rocks  

Sub-Class
Durable Rock, Hard Rock  
Durable Rock, Medium Hardness Rock  

Family
  
  

Group
-  
Volcanic  

Other Categories
Fine Grained Rock, Opaque Rock  
Opaque Rock  

Texture >>
<< Summary

Definition of Greywacke and Obsidian

The general Greywacke and Obsidian definition can be stated as: Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay. On the other hand, 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. Along with definition of Greywacke and Obsidian, get to know about Properties of Greywacke and Obsidian. Get to know more information about Greywacke and Obsidian origin and discoverer, etymology and class.

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History of Greywacke and Obsidian

The history of Greywacke and Obsidian gives information about where the rock was found and who was its discoverer. Almost each and every aspect of Earth's history is recorded in rocks be it the volcanoes which were erupted or the plants, animals and organisms which are now extinct, as rocks are present from millions of years.

Greywacke and Obsidian Origin and Discoverer

Greywacke and Obsidian definition gives us a brief idea about the two rocks. In some cases, the definition also gives summary about the Formation of Greywacke and Obsidian. In this section, you will know about Greywacke and Obsidian Origin and Discoverer. Origin of Greywacke is whereas Origin of Obsidian is Ethiopia. It is interesting to know the name of Greywacke and Obsidian discoverer. The Discoverer of Greywacke is Unknown and the discoverer of Obsidian is Obsius.

Etymology of Greywacke and Obsidian

Along with Greywacke and Obsidian definition, know more about the etymology of Greywacke and Obsidian. Etymology of Greywacke and Obsidian gives information about origin and formation of a particular rock. Know more about Formation of Greywacke and Formation of Obsidian. The etymology of Greywacke is From German Grauwacke, from grau grey + wacke while that of Obsidian is From German Grauwacke, from grau grey + wacke. The process of formation of rocks defines the class of rock. All the rocks in a class are formed by similar processes. Greywacke belongs to Sedimentary Rocks while Obsidian belongs to Igneous Rocks. The sub-class, group and other categories of Greywacke and Obsidian are listed below.

For Greywacke,

For Obsidian,

Sedimentary Rocks

Sedimentary Rocks

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