Granite boulders make impressive cemetery, civic and community memorials that fit naturally into the surrounding environment on which they are placed. Granite boulder monuments offer natural alternatives for monuments and signs. Granite boulder monuments can vary in size and color and may be presented with flattened polished areas for either sandblasted lettering, bronze lettering or bronze plaques.
Granite is a light-colored Igneous Rock with grains large enough to be visible with the unaided eye. It forms from the slow crystallization of magma below Earth’s surface. Granite is composed mainly of quartz and feldspar with minor amounts of mica, amphiboles, and other minerals. This mineral composition usually gives granite a red, pink, gray, or white color with dark mineral grains visible throughout the rock.
Granite ( /ˈɡrænɪt/) is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be predominantly white, pink, or gray in color, depending on their mineralogy. The word “granite” comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a holocrystalline rock. Strictly speaking, granite is an igneous rock with between 20% and 60% quartz by volume, and at least 35% of the total feldspar consisting of alkali feldspar, although commonly the term “granite” is used to refer to a wider range of coarse grained igneous rocks containing quartz and feldspar.
The term “granitic” means granite-like and is applied to granite and a group of intrusive igneous rocks with similar textures and slight variations in composition and origin. These rocks mainly consist of feldspar, quartz, mica, and amphibole minerals, which form an interlocking, somewhat equigranular matrix of feldspar and quartz with scattered darker biotite mica and amphibole (often hornblende) peppering the lighter color minerals. 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 known as a granite porphyry. Granitoid is a general, descriptive field term for lighter-colored, coarse-grained igneous rocks. Petrographic examination is required for identification of specific types of granitoids. The extrusive igneous rock equivalent of granite is rhyolite.
Granite is nearly always massive (lacking any internal structures), hard and tough, and therefore it has gained widespread use throughout human history as a construction stone. The average density of granite is between 2.65 and 2.75 g/cm3 (165.4 – 171.7 lb/ft3), its compressive strength usually lies above 200 MPa, and its viscosity near STP is 3–6 • 1019 Pa·s.
The melting temperature of dry granite at ambient pressure is 1215–1260 °C (2219–2300 °F); it is strongly reduced in the presence of water, down to 650 °C at a few kBar pressure.
Granite has poor primary permeability, but strong secondary permeability.