Leading American analysts say that the international diamond industry has bucked global trends and grown in size, Rough and Polished reports. Boston-based global management consulting firm Bain and Company said that sales of diamond jewelry around the world increased by 18% in 2011 to reached $71 billion, and that the United States accounted for the largest share of this market, $27 billion in total.

In a webcast to launch its report "The global diamond industry – Portrait of Growth", Bain said that the recent increases in the prices of both rough diamonds and polished diamonds results from a reduction in the supply of the former. The amount of rough diamonds marketed annually dropped 3% from 128 million carats in 2010 to 124 million carats in 2011.

Bain also confirmed that the industry would continue to increase in size, thanks to the growth of the middle class in countries like China and India, according to Rough and Polished.