Gneiss and Porphyry Definition

Definition of Gneiss and Porphyry

The general Gneiss and Porphyry 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, Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix. Along with definition of Gneiss and Porphyry, get to know about Properties of Gneiss and Porphyry. Get to know more information about Gneiss and Porphyry origin and discoverer, etymology and class.

History of Gneiss and Porphyry

The history of Gneiss and Porphyry 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 Porphyry Origin and Discoverer

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

Etymology of Gneiss and Porphyry

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

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