Granite ( /ˈɡrænɨt/) is a common widely occurring type of intrusive, felsic, igneous rock which is granular and crystalline in texture. This rock consists mainly of quartz, mica, and feldspar. 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. Granites can be pink to gray in color, depending on their chemistry and mineralogy. By definition, granite is an igneous rock with at least 20% quartz by volume. Granite differs from granodiorite in that at least 35% of the feldspar in granite is alkali feldspar as opposed to plagioclase; it is the alkali feldspar that gives many granites a distinctive pink color. Outcrops of granite tend to form tors and rounded massifs. Granites sometimes occur in circular depressions surrounded by a range of hills, formed by the metamorphic aureole or hornfels. Granite is usually found in the continental plates of the Earth's crust.
Granite 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 is between 2.65 and 2.75 g/cm3, its compressive strength usually lies above 200 MPa, and its viscosity near STP is 3-6 • 1019 Pa·s. Melting temperature is 1215 - 1260 °C.
The word granite comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a crystalline rock.
Granitoid is a general, descriptive field term for light-colored, coarse-grained igneous rocks. Petrographic examination is required for identification of specific types of granitoids.
Other articles related to "granite":
... cliff tombs at Revash, Peru Mount Rushmore, United States – granite Crazy Horse Memorial, United States – pegmatite granite - work in progress Stone Mountain, United States – granite ...
... Also in the churchyard are a granite cross dating from the 19th century which is set on a granite base probably dating from before the Norman Conquest, and stocks dating from the 17th century which are set under a 20th-c ...
... Ceiriog Granite Quarries railway 2 ... ft (610 mm) Criggion, Wales Internal quarry system worked by a single steam locomotive until 1921, when it was replaced by cable-haulage ... Charnwood Granite Quarries railway 1850s 2 ... ft (610 mm) Shepshed, England Early horse worked quarry system steam locomotives introduced in late 1890s, replaced ... under Bardon, England Hauled stone from the Cliffe Hill Granite Quarry ...
... Granite is an unincorporated community in Baltimore County, Maryland, United States ... known as Waltersville, it was renamed Granite in recognition of its principal product (the Woodstock Quartz Monzonite was quarried) ... The Granite Historic District was listed on the National Register of Historic Places in 1994 ...
... Gimblet Rock—is the remains of a large granite outcrop and quarry at Pwllheli, Gwynedd, Wales ... The granite was mined by the Liverpool and Pwllheli Granite Company (sometimes known as the Pwllheli Granite Company), which used the granite for stone setts to pave ...
Famous quotes containing the word granite:
“I make myself this time
Of wood or granite or lime
A wall too hard for crime
Either to breach or climb....”
—Robert Frost (18741963)
“Hell is paved with great granite blocks hewn from the hearts of those who said, I can do no other.”
—Heywood Broun (18881939)
“We placed the wreaths upon the splended granite sarcophagus, and at its feet, and felt that only the earthly robe we loved so much was there. The pure, tender, loving spirit which loved us so tenderly, is above usloving us, praying for us, and free from all suffering and woeyes, that is a comfort, and that first birthday in another world must have been a far brighter one than any in this poor world below!”