KINDS OF ROCKS – The Three Types, Definition And Examples

KINDS OF ROCKS – Igneous, Sedimentary, And Metamorphic With Examples.

KINDS OF ROCKS – In this topic, we will talk about the three kinds of rocks which is: igneous, sedimentary, and metamorphic, and their examples.


First and foremost, let us know the definition of a rock.


A rock is any naturally occurring solid mass or a natural object that is composed of various minerals.

Kinds of rock

Igneous Rocks

These rocks are formed when magma, which is a molten rock from inside the earth, cools and hardens, may it be inside the earth or at the earth’s surface.


  • Basalt – a dark, fine-grained volcanic rock
  • Obsidian – a hard, dark, glasslike volcanic rock formed by the rapid solidification of lava without crystallization.
  • Diorite – a speckled, coarse-grained igneous rock consisting essentially of plagioclase, feldspar, and hornblende or other mafic minerals.
  • Gabbro – a phaneritic, mafic intrusive igneous rock
  • Rhyolite – an igneous, volcanic rock, of felsic composition.

Sedimentary Rocks

They are formed when particles of sand, shells, pebbles, and other fragments of material combined together to what we call sediments, thus the name.


  • Conglomerate – a coarse-grained clastic rock made from substantial fractions of rounded to subangular gravel-size clasts
  • Breccia – a rock made of angular fragments cemented together.
  • Limestone – a carbonate rock that is made of skeletal fragments of marine organisms such as coral, foraminifera, and molluscs.
  • Sandstone – a clastic rock mainly made from mainly of sand-sized mineral particles orrock fragments
  • Shale – a fine-grained, clastic rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite.

Metamorphic rocks

These rocks are formed under the surface of the earth from the change that happens due to intense heat and pressure.

  • Gneiss – a high-grade rock that is formed from granite
  • Marble – a rock that is made of recrystallized carbonate minerals, most commonly calcite or dolomite.
  • Quartzite – A hard non-foliated rock that is previously pure quartz sandstone.
  • Granulite – a fine-grained granular rock that is made of feldspars and quartz.
  • Schist – a coarse-grained rock that consists of layers of different minerals and can be split into thin irregular plates.

READ ALSO: RECYCLED VS INDIGENOUS – The Difference Of The Two Materials

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