The diamond industry
Due to their high dispersion and unsurpassed hardness, diamonds have long been prized as a constituent of jewellery. A large trade in gem-grade diamonds exists, mostly controlled by the De Beers company, which has used its monopoly to manipulate prices. At one time it was thought over 80% of the world's rough diamonds passed through the Diamond Trading Company (DTC, a subsidiary of De Beers) in London, but presently the figure is estimated at c. 60%. In the late 90's, the Canadian prospectors discovered several rich sources of diamonds. For example, the Ekati Diamond Mine, which was opened in 1998, produces 3 million carats of rough diamond every year. The Diavik Diamond Mine was opened in 2004.
Diamonds are valued according to the four C's of diamond grading, namely cut, clarity, color, and carat. Both rough and cut diamonds are graded and separated based on these four characteristics at a number of heavily guarded grading centers, such as the DTC.
Only
diamonds are hard enough to cut other diamonds. Polishing and mounting
add further value, brilliance, and appeal as jewelry.