Granite Rocks : What Is Granite Rock And How Is It Formed?

Granite Rocks
Pink granite sample approximately 1″ (3cm) in size – Large crystals in this felsic plutonic rock

What is Granite?

Granite is a common type of granular and phaneritic felsic intrusive igneous rock. Granites, depending on their mineralogy, can be predominantly white, pink or gray in colour. In reference to the coarse-grained structure of such a holocrystalline rock, the word “granite” comes from the Latin granum, a grain. Strictly speaking, granite is an igneous rock with a volume of between 20% and 60% and at least 35% of the total feldspar consisting of alkali feldspar, although the term “granite” is commonly used to refer to a wider range of coarse-grained igneous rocks with quartz and feldspar.

The term “granite” is used for granite and a group of intrusive igneous rocks with similar textures and slight variations in composition and origin. These rocks consist mainly of feldspar, quartz, mica, and amphibole minerals, forming an interlocking, somewhat equigranular feldspar and quartz matrix with dispersed darker biotite mica and amphibole (often hornblende) peppering the lighter minerals.

Granite is almost always massive, hard and tough (i.e. without any internal structures). Throughout human history, these properties have made granite a widespread building stone. The average granite density ranges from 2.65 to 2.75 g / cm3 (165 to 172 lb / cu ft), its compressive strength is usually above 200 MPa, and its viscosity near STP is 3–6·1019 Pa·s.

How is granite formed?

Granite is more common in continental crust than in oceanic crust and has a felsic composition. They are crystallized by felsic melts that are less dense than mafia rocks and therefore tend to ascend to the surface. Mafic rocks, on the other hand, either basalts or gabbros, once metamorphosed at eclogite facies, tend to sink under the Moho into the mantle.

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Uses of Granite

Granite has many uses as well as interior / exterior design in the construction. It is popular throughout the world and widely used for architectural design. The following are some of the most commonly used granite products:

  1. Granite flooring tiles
  2. Granite wall tiles
  3. Granite slabs for vanity and counter tops, feature walls and kitchen islands
  4. Granite monuments
  5. Granite tombstones
  6. Granite cobbles
  7. Granite paving stones
  8. Granite veneers

Related: Types of Rocks