RAPAPORT... De Beers' rough-diamond sales were seasonally lower in September as Indian factories prepared for the Diwali shutdown, the miner reported Wednesday.Proceeds came to $500 million at the company's eighth sales cycle of the year, which included the sight that ran from September 19 to 23as well as auction revenues. The total was 2% higher than a year earlier but 22% lower than in August, when customers bought $638 million worth of goods.Rough buying tends to slow ahead of Diwali. Many manufacturers are expecting to close for around three weeks from October 24, such that any polished they produce after the festival will likely not be ready in time for the US holiday season."Demand for our rough diamonds during sales cycle eight was in line with expectations at what is a traditionally quieter time of year for the diamond industry as polishing factories in India prepare for closures ahead of the Diwali holidays," said De Beers CEO Bruce Cleaver in a statement. "The steady overall demand for De Beers Group rough diamonds is reflected in the ongoing consumer demand for diamond jewelry ahead of the key holiday sales season in the US."De Beers kept prices mostly steady and is likely to maintain those levels through the end of the year, customers told Rapaport News. That's despite overall weakness in the rough market, with auctions and tenders showing a drop in demand amid a rise in midstream polished inventories.Image: Rough-diamond sorting. (De Beers)