The De Beers Group faced off tricky macro-economic conditions to record first-half earnings before interest tax depreciation and amortisation (Ebitda) of $0.3-billion, with the diamond company’s 50% mining margin the highest within the Anglo American stable. “Operational performance at De Beers has been really good,” Anglo CE Duncan Wanblad told investment analysts and journalists at this week’s half-year results presentation at which Anglo’s overall half-year Ebitda was reported to be a 49%-lower $5.1-billion.