(IDEX Online) - De Beers today reported a 31.5 per cent year-on-year drop in rough sales during June (cycle 5), amid increasing sightholder caution. Provisional sales were $450m, down only a little on $479m the previous month.But on a year-on-year basis, they suggest a marked slowdown. Sales were 4.5 per cent lower than 2022 at cycle 3 and 20 per cent lower at cycle 4. Today's cycle 5 figure is 31.5 per cent down on sales of $657m last year.Al Cook, CEO, De Beers Group, said: "Following the JCK Show, and with ongoing global macroeconomic challenges continuing to impact end-client sentiment, the diamond industry remains cautious heading into summer. "Reflecting this, we saw demand for De Beers rough diamonds during the fifth sales cycle of the year slightly softer than in the fourth cycle."Back in April he spoke of "encouraging positive trends" in consumer demand, especially in China.