Obsidian and Lignite Definition

Definition of Obsidian and Lignite

The general Obsidian and Lignite 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, Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat. Along with definition of Obsidian and Lignite, get to know about Properties of Obsidian and Lignite. Get to know more information about Obsidian and Lignite origin and discoverer, etymology and class.

History of Obsidian and Lignite

The history of Obsidian and Lignite 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 Lignite Origin and Discoverer

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

Etymology of Obsidian and Lignite

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

For Obsidian,

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

For Lignite,

• Sub-class: Durable Rock and Soft Rock
• Group:
• Other Categories: Coarse grained rock, Fine grained rock, Medium grained rock and Opaque rock