Gneiss and Obsidian Definition

Definition of Gneiss and Obsidian

The general Gneiss and Obsidian definition can be stated as: Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks. 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 Gneiss and Obsidian, get to know about Properties of Gneiss and Obsidian. Get to know more information about Gneiss and Obsidian origin and discoverer, etymology and class.

History of Gneiss and Obsidian

The history of Gneiss 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.

Gneiss and Obsidian Origin and Discoverer

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

Etymology of Gneiss and Obsidian

Along with Gneiss and Obsidian definition, know more about the etymology of Gneiss and Obsidian. Etymology of Gneiss and Obsidian gives information about origin and formation of a particular rock. Know more about Formation of Gneiss and Formation of Obsidian. The etymology of Gneiss is From the Middle High German verb gneist (to spark; so called because the rock glitters) while that of Obsidian is From the Middle High German verb gneist (to spark; so called because the rock glitters). The process of formation of rocks defines the class of rock. All the rocks in a class are formed by similar processes. Gneiss belongs to Metamorphic Rocks while Obsidian belongs to Igneous Rocks. The sub-class, group and other categories of Gneiss and Obsidian are listed below.

For Gneiss,

• Sub-class: Durable Rock and Hard Rock
• Group: Not applicable
• Other Categories: Coarse grained rock, Medium grained rock and Opaque rock

For Obsidian,

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