De Beers’ Diamond Trading Company (DTC) said the average cumulative increase in its rough diamond prices since the beginning of 2008 until end August 2008 has been 16.0 %. “The DTC takes a long term, sustainable view on its pricing and decisions are influenced first and foremost by demand for polished,” said Mahiar Borhanjoo, DTC, Executive Director of Sales & Client Services. “So far during 2008, DTC has seen strong and continuing consumer demand for most categories of polished diamonds, especially in the larger goods,” Borhanjoo added.