Proceeds at De Beers’ fourth rough-sales cycle of the year saw a downturn from the recent improvement noted in the last few sights as it entered a traditionally slow period for the industry. The miner brought in $380 million in May, down 21% versus the equivalent period in 2023, it said Thursday. That figure is also 15% lower than the $446 million the company reported at its April cycle, and 12% lower than February’s total.