Diamond is what we often call diamond (diamond is its common name), it is a mineral made of pure carbon. Diamond is the hardest material in nature, so it has many important industrial uses, such as fine grinding materials, high hard cutting tools, various drills and drawing dies. Diamond is also used as a part of many precision instruments. Diamond has a variety of colors, from colorless to black. They can be transparent, or translucent or opaque. Most diamonds are mostly yellow. Diamond has a high refractive index and strong dispersion performance, which is why diamond reflects colorful flashes. The diamond will emit blue green fluorescence under X-ray. Diamond is produced only in Kimberley barrels. Kimberlite is their primary rock, and diamonds in other places are transported by rivers, glaciers and so on. Diamond is generally granular. If the diamond is heated to 1000 ℃, it will slowly become graphite. In 1977, a villager in Changlin, Yishan Township, Linshu County, Shandong Province, discovered the largest diamond in China (about the size of egg yolk, right). The world's largest industrial diamond and gemstone grade diamond are both produced in Brazil, both of which exceed 3100 carats (1 carat = 200 mg), of which the size of gem grade diamond is 10 × 6.5 × 5 cm, called "curinan". In the 1950s, the United States successfully manufactured synthetic diamond from graphite at high temperature and high pressure. Now artificial diamond has been widely used in production and life, but it is difficult to produce large particles of diamond.
Diamond, also known as diamond, is commonly known as diamond diamond. The chemical formula is C, which belongs to the carbon monomer as graphite. It is a kind of excellent physical properties such as super hard, wear-resistant, heat sensitive, heat conduction, semiconductor and far penetration. It is known as "king of hardness" and "king of gemstone". The crystal angle of diamond is 54 degrees 44 minutes and 8 seconds. In the past, people often call the processed diamond, but the unprocessed diamond. In China, diamond is first found in Buddhist scriptures. Diamond is the hardest material in nature, the best color is colorless, but also has special colors, such as blue, purple, golden yellow, etc. These colors of diamonds are rare and are precious in diamonds. India is the most famous diamond producer in history. Now many famous diamonds in the world are like "bright mountain", "Regent king" and "Orlov" are all from India. Diamond production is very rare, usually the finished drilling is one billion of the mining volume, so the price is very expensive. After the diamond is polished, there are generally round, rectangular, square, oval, heart-shaped, pear shaped, olive sharp shape, etc. The heaviest diamond in the world is "curinan", which is produced in South Africa in 1905, weighing 3106.3 carats, and has been divided into 9 small drills. Among them, one of the diamonds named "star of Africa" still occupies the first place in the world.
Crystal structure: the cell is a face centered cubic structure, each cell contains 2 groups of 8 C atoms.
Diamond diamond is usually yellow, brown, blue, green and pink, but it is especially good for colorless diamond. In the world, 10 large gem grade diamonds weighing more than 620 carats (124 g) were found, among which the largest one is Cullinan, which weighs 3106 carats (621.35 g), and is 5 × 6.5 × 10 cm in size. In 1905, it was found in the plemirite tube in South Africa. Changlin diamond, 158.786 carat, was found in Linshu County, Shandong Province in 1977, and is listed as a world famous diamond. The main sources of diamond in the world are Australia, Zaire, Botswana, the former Soviet Union, South Africa, Brazil, Namibia, Garner, Central Africa, Sierra Leone and China.
According to 1987 data, the main diamond metallogenic areas in China are: ① Liaodong Jinnan metallogenic area, and there are two kimberlites in Mesozoic and Middle Paleozoic. ② In the metallogenic areas of Western Shandong, Northern Jiangsu and Northern Anhui, there may be many kimberlites in the lower Paleozoic. ③ Kimberlite has been found in Taihang Mountain, Songshan and Wutai Mountain in Jinyu and Jicheng mining areas. ④ Four diamond placers with industrial value have been found in Yuanshui basin of Hunan Province in Xiangqian Hubei Chuancheng mining area.
Hunan Diamond, produced in Changde Dingjiagang, Taoyuan, Qianyang and other places in Hunan Province. The diamond in Hunan is mainly composed of sand and ore, mainly distributed in Yuanshui River Basin, scattered and low grade, but of good quality, and the gem grade diamond accounts for about 40%. It is said that in Ming Dynasty, there were scattered diamond discoveries in Yuanjiang River Basin of Hunan Province, and large-scale prospecting began in 1950s. Diamond is distributed in the whole water area of Yuanjiang River, but only four places of mining value are Changde Dingjiagang, chexichong, Taoyuan County, Xinzhuang long in Xupu County (Qianyang), yaotou of Yuanling County.
The color of diamond in Hunan is different, the color difference between inside and outside is obvious, and it is distributed in band and spot shape. The brown series diamond has a yellowish brown crystal, clean interior, and a large number of brown spots on the surface. The brown spots are yellow, yellow brown, brown, black, etc. The Brown is mainly distributed on the dissolution surface of diamond, and the brown is mainly caused by the irradiation of radioactive particles in nature. The diamond has small overall particles, but the texture is good, mainly composed of single crystals, accounting for 98% of the total output; the crystal is relatively complete, with octahedron, dodecahedron and hexahedron as the most; most of the crystals are light and transparent or yellow and brown; the grain weight is less than 28mg, generally 10.9-15mg; 22% of the crystals contain inclusions; 60% of the crystal surface has cracks and the surface is not corroded seriously.
