Some of the world's most valuable diamond mines can be found in Sierra Leone. Mining and diamonds have been their economic base. In the 1970's and early 1980's the economic growth rate slowed because of the decline in the mining sector. Sierra leone's formal economy was destroyed by the country's civil war. Most of the civil war fighting was brough about by the control of the mines. So this raises a question in my mind, was the mining and diamond resouces a curse or a blessing for the country? Since the war mining in Sierra Leone is back up and running.
Mining in South Africa has been an economic advantage for Africa. According to wikipedia the profitable mining in South Africa develop when Erasmus Jacobs discovered a diamond along the Orange River. In 2002, South Africa accounted for 15% of the world's gold production. the De Beers Consolidated Mines Company controls much of South Africa's sources of Diamonds. So South Africa's success with gold mining turned out to be beneficial for Africa.