The Origin of Diamond Grading（Ⅰ）

  Because diamonds are difficult to process, before the diamond cutting technology is mature and perfect, the quality of diamonds is determined according to the perfection of the crystal, the brightness of the crystal surface and the weight of the diamond, and the color and clarity do not affect the price.

  Before the 16th century, India was the only producer of diamonds in the world.

  In 1724, with the discovery of Brazilian diamonds, Brazil gradually replaced India as the main producer of diamonds in the world. The diamond resources produced in Brazil have been the main source of diamonds in the world for more than 100 years. As the supply of diamonds continues to increase, people's perceptions of diamond quality are quietly undergoing a major shift, with cut quality gradually replacing crystal form.

  After the discovery of diamonds in South Africa in 1867, a large number of diamond resources were mined, and the output of diamonds increased day by day. Along with the extensive use of diamonds and the development of diamond cutting and grinding technology, people pay more and more attention to the quality of diamond processing. At the same time, the color and clarity of diamonds have also begun to receive more attention from people, and have gradually become important factors in diamond quality evaluation.

  In the mid-19th century, the names of diamond mines such as Golcondo, Bagagem, Canavievas, Diamatinas and Bahias were used to describe the color of diamonds. Among them, Golcondo is an important diamond mine origin in ancient India, and the rest are the names of diamond mines in Brazil. Golcondo represents the best color diamonds, followed by Bagagem Canavieras, Diamantinas and Bahias in that order.

  With the continuous development of the diamond industry, the evaluation of diamond quality has become more stringent, and the terminology for evaluating diamond grades has also changed, forming a color grading term called "old term", that is, a term describing the color grade of diamonds. It became the name of the diamond mine in South Africa, and was divided into Jager, River, Top Wesselton, Wesselton, Crystal and Cape according to the quality of the color. At the same time, the concept of diamond clarity and cut has also been developed.