RAPAPORT... Sales at Lucara Diamond Corp. jumped in the third quarter as the miner recovered higher-value stones and benefited from its supply deal with a Belgian manufacturer.Revenue leaped 76% year on year to $72.7 million for the three months ending September 30, the Canada-based company reported Wednesday. The average selling price almost doubled to $619 per carat from $365 per carat a year earlier.Market prices for rough rose, while the company recovered more diamonds above 10.8 carats from its Karowe mine in Botswana than a year before, Lucara noted. In addition, the miner's arrangement with HB Antwerp, which has agreed to purchase all of Lucara's rough stones weighing 10.8 carats or more, generated revenues of $50.5 million, compared with $25.9 million a year earlier.Meanwhile, sales on the company's Clara online trading platform - which matches buyers with rough based on their polished needs - climbed to $6.6 million versus $2.8 million in the third quarter of 2020."Following a challenging 2020, the diamond market in 2021 continues to be in a healthy balance due to robust demand and lower rough supply," Lucara explained. "The market remained stable in [the third quarter] despite concerns there may be a softening in the Chinese market."Image: The Karowe mine. (Lucara Diamond Corp.)