Firestone Diamonds is considering taking over Kopane Diamond Developments to ultimately form an enlarged group that would be a leading mid-tier diamond producer. It has made an all-share offer worth $70.7 million to Kopane. %% The deal has received approval from the Kopane board and entails Kopane’s Liqhobong project in Lesotho, which Firestone believes is the world's third largest undeveloped kimberlite resource. Firestone predicts the takeover would enable the group to have a production potential of over 1 million carats per annum. %% Currently, Firestone has its operations in Botswana and South Africa.