Obsidian and Greywacke Definition

Definition of Obsidian and Greywacke

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

History of Obsidian and Greywacke

The history of Obsidian and Greywacke 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.

Obsidian and Greywacke Origin and Discoverer

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

Etymology of Obsidian and Greywacke

Along with Obsidian and Greywacke definition, know more about the etymology of Obsidian and Greywacke. Etymology of Obsidian and Greywacke gives information about origin and formation of a particular rock. Know more about Formation of Obsidian and Formation of Greywacke. The etymology of Obsidian is From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius while that of Greywacke is From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius. The process of formation of rocks defines the class of rock. All the rocks in a class are formed by similar processes. Obsidian belongs to Igneous Rocks while Greywacke belongs to Sedimentary Rocks. The sub-class, group and other categories of Obsidian and Greywacke are listed below.

For Obsidian,

• Sub-class: Durable Rock and Medium Hardness Rock
• Group: Volcanic
• Other Categories: Opaque rock

For Greywacke,

• Sub-class: Durable Rock and Hard Rock
• Group:
• Other Categories: Fine grained rock and Opaque rock