De Beers markets its rough diamonds in a series of tightly scripted sales, where handpicked buyers are normally expected to take all their contracted allocations at a price set by De Beers, or face potential penalties in the future. But with prices in free fall around the world, the one-time diamond monopoly has been forced to allow more and more flexibility, finally removing the restrictions altogether.The concessions are the latest in a series of increasingly desperate moves across the industry to stem this year’s plunge in diamond prices, after slowing consumer demand left buyers stuck with swelling inventories. De Beers’s great rival, Russian miner Alrosa PJSC, already canceled all its sales for two months, while the market in India — the dominant cutting and trading center â€â€¦