List of rock types

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The following is a list of rock types recognized by geologists. There is no agreed number of specific types of rock. Any unique combination of chemical composition, mineralogy, grain size, texture, or other distinguishing characteristics can describe a rock type. Additionally, different classification systems exist for each major type of rock. [1] There are three major types of rock: igneous rock, metamorphic rock, and sedimentary rock.

Contents

Igneous rocks

A sample of andesite (dark groundmass) with amygdaloidal vesicles filled with zeolite. Diameter of view is 8 cm. Amygdaloidal andesite.jpg
A sample of andesite (dark groundmass) with amygdaloidal vesicles filled with zeolite. Diameter of view is 8 cm.

Sedimentary rocks

Bituminous coal seam in West Virginia Coalseam 8618.JPG
Bituminous coal seam in West Virginia
Limey shale overlaid by limestone. Cumberland Plateau, Tennessee Limestoneshale7342.jpg
Limey shale overlaid by limestone. Cumberland Plateau, Tennessee
Dolomite crystals from Touissite, Morocco Dolomite Morocco.jpg
Dolomite crystals from Touissite, Morocco
Turbidite (Gorgoglione Flysch), Miocene, South Italy Turbidite 2.JPG
Turbidite (Gorgoglione Flysch), Miocene, South Italy

Metamorphic rocks

Phyllite PhylliteUSGOV.jpg
Phyllite
Banded gneiss with a dike of granite orthogneiss Skagit-gneiss-Cascades.jpg
Banded gneiss with a dike of granite orthogneiss
Marble MarbleUSGOV.jpg
Marble
Quartzite Quartzite 2 jpg.jpg
Quartzite
Manhattan Schist, from Southeastern New York Schist.jpg
Manhattan Schist, from Southeastern New York
Slate SlateUSGOV.jpg
Slate

Specific varieties

The following are terms for rocks that are not petrographically or genetically distinct but are defined according to various other criteria; most are specific classes of other rocks, or altered versions of existing rocks. Some archaic and vernacular terms for rocks are also included.

See also

References

  1. "BGS Rock Classification Scheme - Igneous - Metamorphic - Sedimentary - Superficial". British Geological Survey (BGS). Retrieved 2019-05-28.