The earliest diamonds were found in India in 4th century BC, although the youngest of these deposits were formed 900 million years ago. A majority of these early stones were transported along the network of trade routes that connected India and China, commonly known as the Silk Road. At the time of their discovery, diamonds were valued because of their strength and brilliance, and for their ability to refract light and engrave metal. Diamonds were worn as adornments, used as cutting tools, served as a talisman to ward off evil, and were believed to provide protection in battle. In the Dark Ages, diamonds were also used as a medical aid and were thought to cure illness and heal wounds when ingested. Until the 18th century, India was thought to be the only source of diamonds. When the Indian diamond mines were depleted, the quest for alternate sources began. Although a small deposit was found in Brazil in 1725, the supply was not enough to meet world demands.
The story of the modern diamond market really begins on the African continent, with the 1866 discovery of diamonds in Kimberley, South Africa. Entrepreneur Cecil Rhodes established De Beers Consolidated Mines Limited 22 years later, in 1888. By 1900, De Beers, through its mines in South Africa, controlled an estimated 90 percent of the world’s production of rough diamonds. The South African sources affected many segments of the diamond industry. This was especially true as diamond mining moved from the surface to farther underground. Because of the huge costs and comparatively low yields involved, the new sources forced the development of more efficient mining techniques. They created the need for better marketing. They also led to advances in cutting and polishing—advances that increased efficiency, reduced costs, and enhanced the appearance of finished stones.
World diamond mining expanded dramatically with the discovery of sources in Australia in 1985 and important new deposits in northern Canada in 2000. The market probably changed as much after 1990 as it did in the years after the 1866 discovery of diamonds in South Africa and the establishment of De Beers. The 1990s brought exciting new sources and encouraged the dramatic growth of some cutting centers. All this was happening as the world economy fluctuated wildly. As one of the trade’s major participants, De Beers had to change, too. The De Beers of today bears little resemblance to the De Beers of 1989. The company greatly reduced its role as the custodian of diamond supply. Instead of flowing into the market in a single-channel path from De Beers, diamonds now flow into the market through multiple channels.
Diamond’s splendor has been appreciated for centuries, but there was not much scientific knowledge about it before the twentieth century. Since then, diamond knowledge has grown steadily, with research by chemists, physicists, geologists, mineralogists, and oceanographers. In the past 50 years alone, scientists have learned a lot about how diamonds form and how they’re transported to the earth’s surface. That knowledge has made it easier to predict locations for new diamond discoveries.