What is the hardness range of granite?
The granite has a specific gravity of between 2.63 and 2.75 and has a compressive strength of 1,050 to 14,000 kg / cm2 (15,000 to 20,000 pounds per square inch) because the strength of the granite is greater than that of sandstone, limestone and marble. Granite formation of the special conditions and firm structural characteristics, it has the following unique performance:
(1) has a good decorative performance, applicable to public places and outdoor decoration.
(2) with excellent processing performance: saw, cut, polished, drilling, sculpture, etc. Its processing accuracy of up to 0.5μm below the luminosity of more than 1600.
(3) wear resistance is good, 5-10 times higher than cast iron.
(4) thermal expansion coefficient is small, not easy to deformation, and indium steel is similar to the temperature affected by minimal.
(5) elastic modulus, higher than cast iron.
(6) Rigid, internal damping coefficient, 15 times larger than steel. Can shock, shock.
(7) granite with brittle, damaged only partial loss, does not affect the overall straightness.
(8) granite chemical stability, not easy weathering, acid, alkali and corrosive gas erosion, the chemical and silica content is proportional to the service life of up to 200 years.
(9) granite with non-conductive, non-magnetic, field stability.
Although granite is thought to be igneous from the melted material or magma, there is a lot of evidence that some granite formation is a partial deformation or a product of a previous rock that is rearranged and recrystallized without a liquid or melting process.
Granite is igneous, formed by underground magma jet and intrusion cooling, as well as granitic metamorphic rocks, etc. It has visible crystal structure and texture, it consists of feldspar (usually potassium feldspar and amphibole) and quartz composition, Mixed with a small amount of mica (biotite or muscovite) and trace minerals, such as: zircon, apatite, magnetite, ilmenite and stone, etc. Granite is the main component of silica, its content About 65% -85%. The chemical properties of granite are weakly acidic.Often, the granite is slightly white or gray, with the dark crystal, the appearance of the spot with the addition of potassium feldspar Red or flesh. Granite is slowly cooled by the magma and crystallized, buried deep below the surface. When the cooling rate is unusually slow, it forms a very coarse texture of granite, which is called crystalline granite. Granite and other crystal rocks Constitute the basis of the continental plate, it is also exposed to the Earth's most common intrusive rocks.
