De Beers’ Diamond Trading Company (DTC) has made it official, that it has increased the price of its diamonds. In a letter to its sightholders DTC declared that the increase was by an average 8.5 percent, taking into account the next week’s sight.

In the January 2008 sight, DTC has announced an increase in its price list by an average of 3.5% across the range of rough diamonds. DTC had simultaneously stated that it would inform the industry on price adjustments in February, May and August to coincide with major trade fairs and key selling periods.

The letter informed that the cumulative effect of the sight by sight changes over the first four sights of 2008 will be an average of +8.5%. The increase will largely concentrate in rough boxes that produce IF to SI polished, which have shown to generate the highest demand and maximum increase in polished prices.