Diamonds may enjoy a luxury status that copper or cobalt will never have - but what connects them is the legacy of exploitation and suffering involved in their trade. The civil war in Sierra Leone in the 1990s,for example,was as infamous for the blood diamonds that funded it as for the conflict itself.Civilians have never profited from trade in the precious stones,but Botsuana - source of one in three of the world’s diamonds - is now bucking the trend. The government there has channeled millions of dollars in profits from the diamond business into public infrastructure,schools and health care. The progress in general prosperity won former president Festus Mogae the 2008 Mo Ibrahim Prize for Achievement in African Leadership.