Gneiss and Tonalite Definition

Definition of Gneiss and Tonalite

The general Gneiss and Tonalite 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, Tonalite is a coarse-grained plutonic rock consisting mainly of sodic plagioclase, quartz, and hornblende or other mafic minerals with phaneritic texture. Along with definition of Gneiss and Tonalite, get to know about Properties of Gneiss and Tonalite. Get to know more information about Gneiss and Tonalite origin and discoverer, etymology and class.

History of Gneiss and Tonalite

The history of Gneiss and Tonalite 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 Tonalite Origin and Discoverer

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

Etymology of Gneiss and Tonalite

Along with Gneiss and Tonalite definition, know more about the etymology of Gneiss and Tonalite. Etymology of Gneiss and Tonalite gives information about origin and formation of a particular rock. Know more about Formation of Gneiss and Formation of Tonalite. The etymology of Gneiss is From the Middle High German verb gneist (to spark; so called because the rock glitters) while that of Tonalite 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 Tonalite belongs to Igneous Rocks. The sub-class, group and other categories of Gneiss and Tonalite 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 Tonalite,

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