Rock (geology)



   

In geology, rock is a naturally occurring aggregate of metamorphic. Petrology is the scientific study of rocks.

Rock classification

 

See also: formation of rocks

Rocks are classified by mineral and breccias or in the case of individual stones. The transformation of one rock type to another is described by the geological model called the rock cycle.

basalt) .[1]

dolostone).[1]

recrystallisation).[1] There are also Foliated and nonfoliated rock types.

The three classes of rocks: the igneous, the sedimentary and the metamorphic — are subdivided into many groups. There are, however, no hard and fast boundaries between allied rocks. By increase or diminution in the proportions of their constituent minerals they pass by every gradation into one another, the distinctive structures also of one kind of rock may often be traced gradually merging into those of another. Hence the definitions adopted in establishing rock nomenclature merely correspond to selected points (more or less arbitrary) in a continuously graduated series. This is frequently urged as a reason for reducing rock classification to its simplest possible terms, and using only a few generalized rock designations. But it is clear that many apparently trivial differences tend regularly to recur, and have a real significance, and so long as any variation can be shown to be of this nature it deserves recognition.[2]

Coloration

chlorite.[2]

Impact on society

 

Rocks have had a huge impact on the cultural and technological advancement of the human race. Rocks have been used by Homo sapiens and other hominids for millions of years. Lithic technology marks some of the oldest and continuously used technologies. The mining of rocks for their dimension stone.

See also

References

  1. ^ a b c Blatt, Harvey and Robert J. Tracy, 1996, Petrology, W. H. Freeman, 2nd ed. ISBN 0-7167-2438-3
  2. ^ a b This article incorporates text from the Encyclopædia Britannica Eleventh Edition article "Petrology", a publication now in the public domain.
 
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