It is available in a wide range of colours and is commonly cut in many ways.
In mineralogy, granites are magmatic rocks (acid plutonic rocks) of idiomorphic granular texture with medium to coarse grain.
The colour generally depends on that of the orthoclase it contains and ranges from white to pink to red.
Together with granodiorites, they are the most common intrusive igneous rocks of the Earth's crust and are the result of slow cooling of magma that atypically consists of silicates, notably quartz (SiO2).
Commercially speaking and according to standard EN 12670:2001, a granite is however defined as a compact rock that may be polished, consisting of quartz, feldspars and with hardness between 5 and 7 Mohs. Serizzo gneiss, beola orthogneiss, porphyry, syenite, diorite, quartzite are thus also included.
Although considerably more difficult to work than marble, granite was used in a number of applications as early as the Egyptian pre-dynastic period, up to the monumental constructions, including the huge obelisks, 200/300 tonne monoliths, erected in a special pink granite exactly called Spire Granite, quarried in Aswan. Use of this ornamental stone peaked in ancient Rome from the end of the 1st century A.D. (under the Flavii dynasty) until the end of the 3rd century A.D. The need to import it from faraway Egypt restricted its use to the higher prized decorative items.
Tonalite, a gneiss similar to white granite, was also originally quarried by the Egyptians. The so-called 'Granite of the Forum' used for Trajan's Forum in Rome comes from the Red Sea Mountains.