Diamond
Diamond is indeed one of the rarest natural resources that have continued to rake in millions of revenue for most countries. Africa is lucky to have this precious gem, with countries such as Botswana, South Africa, Angola, and DR Congo topping the list of the largest diamond producers. As a matter of fact, Botswana is the largest diamond-producing country in the world at the moment. In 2015, the South African country is estimated to have produced close to $4 billion worth of diamonds.
