Obsidian and Rapakivi Granite Definition

Definition of Obsidian and Rapakivi Granite

The general Obsidian and Rapakivi Granite 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, Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase. Along with definition of Obsidian and Rapakivi Granite, get to know about Properties of Obsidian and Rapakivi Granite. Get to know more information about Obsidian and Rapakivi Granite origin and discoverer, etymology and class.

History of Obsidian and Rapakivi Granite

The history of Obsidian and Rapakivi Granite 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 Rapakivi Granite Origin and Discoverer

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

Etymology of Obsidian and Rapakivi Granite

Along with Obsidian and Rapakivi Granite definition, know more about the etymology of Obsidian and Rapakivi Granite. Etymology of Obsidian and Rapakivi Granite gives information about origin and formation of a particular rock. Know more about Formation of Obsidian and Formation of Rapakivi Granite. The etymology of Obsidian is From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius while that of Rapakivi Granite 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 and Rapakivi Granite belong to Igneous Rocks. The sub-class, group and other categories of Obsidian and Rapakivi Granite are listed below.

For Obsidian,

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

For Rapakivi Granite,

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