granitiche

Granitiche is a term used in geology to describe rocks with granitic composition—rocks commonly called granites in English. The granitic family, or granitoids, includes granite and related rock types such as granodiorite, tonalite, and leucogranite. These rocks are felsic igneous rocks, rich in silica and alkali feldspar, with quartz as a major constituent and relatively low contents of ferromagnesian minerals. The typical mineral assemblage is quartz, potassium feldspar, and plagioclase, with minor biotite, hornblende, or muscovite.

Texture is usually phaneritic, meaning the crystals are large enough to see with the naked eye, reflecting slow cooling at depth. Some granitic rocks show porphyritic textures, with large crystals embedded in a finer-grained matrix.

Granitiche rocks form from crystallization of magmas that originate by partial melting of crustal rocks or by differentiation of mantle-derived magmas. They commonly crystallize in plutonic settings within the continental crust, forming batholiths and other large intrusive bodies. Uplift and erosion later expose these rocks at the surface.

Geologically, granitic rocks are widespread on continents, especially in ancient crustal blocks and along convergent-margin belts. They are typically light-colored, with high resistance to weathering, and are widely used as building and decorative stones. The term granitic (granitiche) also denotes rocks with similar mineralogy that may be more variable in composition, from tonalite to granodiorite to granite.