Composition, classification and use of granites
Release time: 2017-09-14 Author: China Stone Network
The main composition of the ore granite alkali feldspar and quartz. Usually feldspar is more than quartz, and both are embedded in each other. Granite unique physical characteristics, coupled with its beautiful patterns, so that he has become a good building materials, known as the "king of rock" said, but also with one view, two volume, three listen, four test to evaluate the good or bad. In construction, granite can be used from roof to floor, and the sidewalk is also made of cement or rock fill dam if crushed. Many need or need for local resistance exposed to wind and rain or the goods are made of granite.
Granite is granular crystalline rocks, the main composition of the ore is alkali feldspar and quartz. Usually more than quartz feldspar content, two mutually embedded tissue occurrence has the following three categories: (1) different components of alkali feldspar separate output, (2) different alkali feldspar with shape material into solid melt or twin shaped intergrowth, (3) and calcium feldspar into solid melt caused by polysynthetic twin intergrowths but, where 80-85% is albite. Alkaline feldspar in petrology is called feldspar, plagioclase, albite, and feldspar, or the synthesis of solid melt from the above feldspar, the albite contains sodium feldspar molecular percentage is not low 80%. Potassium feldspar (feldspar or micro plagioclase molecule) and albite molecular formula are represented by K (Al, Si3O8) and Na (Al, Si3O8), respectively. The molecular formula of calcium feldspar is CaAl2 Si3O8. Calcium feldspar and albite can form solid melts of various proportions, i.e. mineralogy, so-called plagioclase minerals, or calcium albite.
According to the different parts of the world composition 2485 granite average, according to the weight percentage from heavy to light: the mineral composition of SiO2 - 72.04% Al2O3 - 14.42% K2O - 4.12% Na2O - 3.69% CaO - 1.82% FeO - 1.68% Fe2O3 - 1.22% MgO - 0.30% 0.71%TiO2 - P2O5 - 0.12%MnO - 0.05% different varieties of endless the same may also contain clinopyroxene and amphibole. Granite hard texture, dense, high strength, resistance to weathering, corrosion resistance, abrasion resistance, low water absorption, beautiful color can also be preserved for more than a hundred years, is a good building material, but it is not heat-resistant. The granite stones are divided into different grades according to the factors of color, pattern, luster, structure and material. The Mineral Bureau of the Ministry of economic affairs of Taiwan divided granite into black, brown, green, gray, light red and deep red six categories.
According to the containing minerals, can be divided into black granite and muscovite granite, hornblende granite, two mica granite etc.;
According to the structure, can be divided into fine grained granite, medium grained granite, coarse grained granite, porphyritic granite, granite, porphyritic MIAROLITIC granite and gneissic granite; in accordance with the accessory minerals, can be divided into cassiterite bearing granite, granite, iron containing niobium beryllium, lithium mica granite, granite tourmaline granite. Common metamorphism of feldspar, dolomitization, electrical and petrochemical processes. Granite is a widely distributed rock, which has been produced in every geological age. Shape is rock, rock, rock clock line.
The physical properties of granite and its richly endowed by nature beautiful pattern makes him become the building of good material, known as the "king of rock", a view, two, three, four to try to evaluate the quality by others. In construction, granite can be used from roof to floor, and the sidewalk is also made of cement or rock fill dam if crushed. Many need or need for local resistance exposed to wind and rain or the goods are made of granite. The brand of the memorial hall in Taipei and the monument to the people's Heroes at Tiananmen in Beijing are all made of granite. The characteristics of granite after a thousand years still enduring, the famous Egyptian pyramids has proved this point. Granite structure is uniform, hard texture, beautiful color, is a high-quality building stone. The compressive strength varies according to the variety of stone and the place of origin, and is about 1000-3000 kg / cm. Granite weathering, beautiful color, appearance and color can be maintained for more than a century, due to its high hardness and abrasion resistance, except for senior architectural engineering, the ground outside the hall, or open first choice for carving wood.
Commercial including the granite, granite gneiss, schist and granite gneiss granite rocks and scholars called syenite, granodiorite composition between the. Rocks of the gneisses include mineral composition, granite like, and crystalline crystalline organizer. Commercial granite also includes other similar structures, long stone crystals with minor amounts of accessory minerals, mainly decorative, such as rock salt called plagioclase. Gneiss is a coarse crystalline rock, mainly composed of silicate minerals. It is a mosaic and granular crystalline structure, and different minerals are arranged in a regular or irregular arrangement. According to the American Society for testing and testing of materials, granite is divided into two types: plain granite and black granite. The ordinary granite is composed of quartz and feldspar, marble etc., because the colored mineral with black or dark green, often by the whole about the color of feldspar. Black granite dark green or black rock composed of plagioclase, olivine, pyroxene, hornblende and rock, so black granite is divided into coarse spot rock, diabase, Xuan Wuyan three