$1bn diamond sales by De Beers and Alrosa PJSC may be much too soon

The world’s two biggest diamond miners have just sold $1bn worth of gems and it is making smaller rivals nervous.

January offerings by De Beers and Russia’s Alrosa PJSC, which control almost two thirds of the market, far exceeded everyone’s expectations.

The sales were driven by supply cuts last year that led to shortages, lower prices and better-than-expected holiday demand.