The Origin Of Granite Stone

Granite stone is a common and widely occurring type of intrusive, felsic, igneous rock. Granite stone usually has a medium to coarse grained texture. Occasionally some individual crystals (phenocrysts) are larger than the groundmass in which case the texture is known as porphyritic. A granitic rock with a porphyritic texture is sometimes known as a porphyry. Granite stone can be pink to gray in color, depending on their chemistry and mineralogy. By definition, granite stone has a color index (i.e. the percentage of the rock made up of dark minerals) of less than 25%. Outcrops of granite tend to form tors, and rounded massifs. Granite stone sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels.
Granite stone is nearly always massive (lacking internal structures), hard and tough, and therefore it has gained widespread use as a construction stone. The average density of granite stone is located between 2.65 and 2.75 g/cm3, its compressive strength usually lies above 200 GPa and its viscosity at standard temperature and pressure is ~4.5 • 1019 Pa·s.
The word granite stone comes from the Latin granum, a grain, in reference to the coarse-grained stone structure of such a crystalline rock.