The Diamond Trading Company (DTC) raised rough diamond prices at this week's March sight, which sold an estimated $500 million.

DTC spokeswoman Louise Prior confirmed that the company had adjusted prices in most categories of rough production but did not provide additional details. Prior said that the DTC took a stable and long-term approach to pricing policy and did not make decisions in haste.

Sightholders who participated in the March sight, held in London, noted that prices were up across the board that the prices of 2-carat+ diamonds rose by a "high" single digit while diamonds from India cost 25% more.

The price hike of the March sight comes after the DTC raised prices at its February sight by an average of 7%.