Variolite and Coal Definition

Definition of Variolite and Coal

The general Variolite and Coal definition can be stated as: Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance. On the other hand, Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds. Along with definition of Variolite and Coal, get to know about Properties of Variolite and Coal. Get to know more information about Variolite and Coal origin and discoverer, etymology and class.

History of Variolite and Coal

The history of Variolite and Coal 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.

Variolite and Coal Origin and Discoverer

Variolite and Coal definition gives us a brief idea about the two rocks. In some cases, the definition also gives summary about the Formation of Variolite and Coal. In this section, you will know about Variolite and Coal Origin and Discoverer. Origin of Variolite is France whereas Origin of Coal is USA. It is interesting to know the name of Variolite and Coal discoverer. The Discoverer of Variolite is Unknown and the discoverer of Coal is John Peter Salley.

Etymology of Variolite and Coal

Along with Variolite and Coal definition, know more about the etymology of Variolite and Coal. Etymology of Variolite and Coal gives information about origin and formation of a particular rock. Know more about Formation of Variolite and Formation of Coal. The etymology of Variolite is From Latin varius, speckled, variegated while that of Coal is From Latin varius, speckled, variegated. The process of formation of rocks defines the class of rock. All the rocks in a class are formed by similar processes. Variolite belongs to Igneous Rocks while Coal belongs to Sedimentary Rocks. The sub-class, group and other categories of Variolite and Coal are listed below.

For Variolite,

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

For Coal,

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