BOTSWANA’S economy will rebound and grow 7.7% in 2021 from an 8.9% contraction forecast this year, on the back of improved sentiment in the global diamond industry, according to the finance minister. Botswana's economy shrank by 24% in the second quarter of 2020 as coronavirus lockdowns at home and abroad slowed domestic economic activity and severely constrained diamond sales. Buyers of the precious gem were locked out of the capital Gaborone, where they come to purchase diamonds from De Beers. Mining is the sparsely populated southern African country's biggest revenue earner and accounts for just under 20% of total gross…