The main diamond cutting and grinding centers in the world are Antwerp, Tel Aviv, new york, Mumbai, Thailand and Bangkok. Antwerp has a reputation as the diamond capital of the world, and about half of the world's diamond transactions are completed here. "Antwerp Cutting" is synonymous with perfect cut.
Namibia
As far as the ratio of rough diamonds to gem-grade diamonds is concerned, the best diamonds come from diamonds mined in alluvial deposits in Namibia. These diamonds were naturally weathered and transported to the seaside 1000 miles. After this journey, the fragile part of the diamond was separated. In a specific sedimentary environment, diamonds are regularly distributed in rock layers according to different particle sizes and shapes. The highest gem-grade diamonds in this mining area are as high as 97%. It is difficult to distinguish which country and which mining area cut and polished the diamond ring surface.
Diamonds produced in any mining area are good, medium and poor. Comparing the best diamonds in the mining area with the worst diamonds produced in Namibia, the diamonds in alluvial deposits in Namibia are not necessarily good.
India
India was the first country in the world to find diamonds. 3000 years ago, India was the only place where diamonds were produced. From 2500 years ago to the beginning of18th century, the Krishna River, Penna River and their tributaries in India were the only places in the world where diamonds were produced. Many famous diamonds in history, such as kohi-noor, orloff, great mogul, etc., are from India, but the diamond production in India is very small.
Brazil
By 1725, the discovery and mining of Brazilian diamonds made Brazil replace India and become the most important diamond producing area in the world.
South Africa
After 1867, alluvial sand deposits and a large number of primary kimberlite cones were discovered in South Africa, making South Africa the most important diamond producer in the world, and its output has been in the forefront of the world for a long time, thus creating a new era of diamond industry. 1905, the world's largest kimberlite cone-Primir cone was discovered in Jalia, South Africa, where the largest diamond (Cullinan diamond) was found. South Africa has the largest and most modern Venice diamond mine in the world. South Africa's diamonds are large in size and high in quality. 50% of diamonds are machinable. Although the output is not as good as Australia and other countries, the output value has always been in the forefront of the world.
Australia
From 1979, where diamonds were found in K-Mg porphyry in Western Australia, to 1986, Australia's diamond production is dominant, but the gem grade only accounts for 5% of its production. Australian diamonds are mainly distributed in Bingala and Copton, New South Wales, Western Australia, especially the argle deposit, with a reserve of 550 million carats.
Botswana
Rich in high-quality diamonds, the gem grade accounts for 50%, and the output value ranks first in the world. Botswana's diamonds come from kimberlite mined in the open pit. Huge mines include Olapa rock pipe (1967), Letihakkena rock pipe (1977) and Jiwaneng drilling mine (1982). The total output of the three mines exceeded 1500 in 1989.
Russia
Russian diamonds are mainly distributed in Yakutia region in central Siberia, where more than 100 kimberlite cones containing diamonds have been found. 1988, Russia discovered a new diamond mine near Europe. Russia's diamond production is about120,000 carats, half of which are gem-grade. Over the years, Russia has formed an independent diamond mining, processing and sales system, with a large number of diamonds, excellent quality and good uniformity, which is highly competitive in the market.
Canada
A few years ago, it was reported that a large number of kimberlites were discovered in northern Canada. In a few years, diamond production may account for 10% of world production.
1871July 16, the cooperative mining team in Fort Koulis was successful. They dug deep in the land covering tens of square meters and finally found the diamond they dreamed of on this day. The world's first diamond mine was born. The name "Koulis Fort Mine" is also called "New Thermal Wave Mine".
South Africa
Adamantane produced in South Africa is famous for its large particles and good quality. 50% of the rough diamond quartz clocks mined from mines can reach the gem level. More than 50 years ago, South Africa ranked first in the world in diamond production. With the passage of time, South Africa's diamond production has decreased year by year. 1987, South Africa's diamond output was 100000 carats, accounting for about 10% of the world's total output.
In August 1965, a 198-carat white diamond was found in the flagship mine of Lesotho, a landlocked country in southern Africa. This extraordinary white diamond is of high quality and flawless. This diamond can be sold for "more than100000 dollars, and may reach150000 dollars."
China
China's proven diamond reserves and output rank around 10 in the world, with an annual output of 200,000 carats, which are mainly distributed in Wafangdian, Liaoning, Mengyin, Shandong and Yuanjiang, Hunan. Wafangdian, Liaoning Province is currently the largest diamond mine in Asia.
China discovered kimberlite and diamond primary deposits in Guizhou and Shandong in 1965. 197 1 A primary diamond deposit was discovered in Wafangdian, Liaoning Province. The two primary diamond deposits still being mined are located in Wafangdian, Liaoning Province and Mengyin, Shandong Province. Diamond placers are found in Yuanjiang river basin in Hunan, Tibet and Guangxi and Tancheng-Lujiang fault across Jiangsu and Anhui provinces.
There are three main diamond producing areas in China: Wafangdian in Liaoning, Mengyin-Linshu in Shandong and Yuanjiang Valley in Hunan. All of them are kimberlite type, but no primary ore has been found in Hunan. Among them, Liaoning has better quality and Shandong is bigger.
The largest diamond found in China is Chang Lin Diamond, which was discovered in Shandong on February 2 1 977 65438+and was discovered by Wei of Chang Lin Brigade, hence the name "Chang Lin Diamond" and is now in the bank vault. Chang Lin diamond weighs 158.786 carats and is octahedral, with clean, transparent and light yellow texture.
It is also said that the largest diamond in China is Jinji diamond, which was also found in this area, weighing 28 1.25 carats, but it was plundered by the Japanese army during World War II, and its whereabouts are still unknown.