The formation of granite

   （One）Granite. Granite is igneous, emitted by underground magma intrusion and cooling crystallization, and the granite and metamorphic rocks formed. Visibility is the crystal structure and texture. It consists of feldspar (usually K-feldspar and Austrian feldspar) and composed of quartz, mica Adulteration a small number of (black mica or muscovite) and trace minerals, for example: zircon, apatite, Magnetite, ilmenite and drilling stone, and so on. Granite main ingredient is silica, its content is about 65% -85%. The chemical nature of granite was weak acid. Under normal circumstances, white or gray granite slightly, mixed with dark crystal, with the appearance of spots, the addition of K-feldspar makes its red or ginger.

    Granite from the crystallization of magma cooling slowly, buried in the ground, very slow cooling rate, it would create a very rough texture of granite, known as crystalline granite. Granite and other crystalline rocks form the basis of continental plates, it is also exposed to the surface of the Earth the most common intrusive rocks.

    Although granite is considered material by melting or magma formation of igneous rocks, but there were some substantial evidence that the formation of granite or local deformation of the rock previously, they had not been liquid or rearrange the melting process and recrystallization.

    Granite from 2.63 to 2.75 in the proportion between the compressive strength of 1,050 to 14,000 kg / cm 2 (15,000 to 20, 000 pounds / square inch). Because of the strength of granite than sandstone, limestone and marble, and therefore more difficult to mining. The granite formation of the special conditions and strong structural features, it has the following unique features:

    (1)A good decorative properties, applicable in public places and indoor decoration. China Granite can be made of countertop, tombstone, blind stone, Sculpture, roadside stone, ect. Granite products.

    (2)With excellent processing properties: sawing, cutting, grinding, drilling, such as carving. Its processing accuracy of 0.5 μ m luminosity of more than 1,600.

    (3)Wear resistance, 5-10 times higher than iron

    (4)Coefficient of thermal expansion of small and difficult to deformation, and indium similar to steel, the temperature effect is minimal.

    (5)The modulus of elasticity than iron

    (6)Rigid, the damping, than the steel 15 times. Can earthquakes, damping.

    (7)Granite is brittle, damaged after only partial loss will not affect the overall flatness of.

    (8)Granite nature of the chemical stability, not morals to acid, alkali and gas corrosion erosion, chemical and silica content in direct proportion to life up to 200 years.

    (9)Granite is not conductive, magnetic, field of stability.

    Usually, granite is divided into three different categories:

    Fine-grained granite: feldspar crystals average diameter of 1 / 16 to 1 / 8 inch.

    The granite tablets: feldspar crystals average diameter of about 1 / 4 inch.

    Coarse-grained granite: feldspar crystals average diameter of about 1 / 2 inch diameter and larger crystals, and some have even reached a few centimeters. Coarse-grained granite density is relatively low.

    In recent years, the monument building used by the Stones, 83% of granite, marble and 17%.