(IDEX Online) - Lucara has reported a slump in quarterly revenue and profits, blaming a shortage of the high-value specials that account for most of its income.The Canada-based miner said revenue was down 31 per cent year-on-year from $72.7m to $49m and net profits plunged 86 per cent from $12.8m to $1.8m (all figures are US dollars).It sold 99,301 carats in the three months to 30 September 2022, down from 117,162 for the same period last year, and the average price per carat fell from $596 to $377.Since 2020 Lucara has sold all its +10.8-cts gem quality diamonds through HB Antwerp. Revenue from the agreement was $50.5m in Q3 2021, buoyed by the sale of four pink diamonds and two huge Type IIa top white gem diamonds (393.5 carats and 257.5 carats).In Q3 2021 the HB Antwerp sales, which have historically accounted for up to 70 per cent of Lucara's revenue, fell by almost half to $27.1m.Lucara owns and operates the Karowe mine in Botswana, which has been operational since 2012.Pic shows a huge fancy pink Type IIa diamond - weighing 62.7 carats - recovered from the Karaowe mine last year.