After the third century, diamonds disappeared in the Mediterranean region for about 1000 years. One of the main reasons is that with the decline of the Roman Empire, the Persian Empire rose between India and the Mediterranean, replacing the Roman Empire and becoming the main absorber of Indian diamonds. In addition, the death knell of the decline of the Roman Empire was accompanied by the rise of Christianity. Because most of the previous diamonds were related to pagan superstitions, the interest of Christians who just converted to Christianity gradually decreased. Brazilian diamonds once made the world diamond industry prosperous, but their supply was limited. By 186 1, the annual diamond production in Brazil dropped to 170000 carats, and by 1880, the annual diamond production in Brazil was only 5000 carats. The impact of the sharp decline in output on the European diamond industry at that time can be imagined. At this time, a mysterious continent-Africa came with joy and news. 1866 In the summer, a boy of 15 years old found a diamond weighing 2 1.25 carats at Dake Farm on the bank of the Orange River. Later, the diamond was cut into 10.73-carat oval diamond, which was originally named "O'Reilly". When this diamond appeared in the World Expo held in Paris in 1889, it was easily named "Eureka". After the appearance of South African diamonds, Kimberly discovered a huge diamond deposit. During the period of 1872- 1903, the annual output of diamonds mined by various deposits around Kimberly City reached 20-30 million carats, accounting for 95% of the global total diamond output. Due to the discovery of diamonds in South Africa, De Beers, the largest diamond company in the world, was established, and a very prosperous modern diamond industry was born.