Diamond - Diamond is the hardest known natural substance and one of the oldest geologically speaking. Formed from almost completely pure carbon crystals more than 150 kilometers below the Earth's surface, some are as old as three billion years! As far back as antiquity, this stone of incomparable brilliance was described as the symbol of luxury and opulence. Until the end of the 19th century, there were only two known sources of supply: India and Brazil. At the end of the 15th century, as Portuguese navigators inaugurated the sea routes to these countries, Jews living in Lisbon began cutting and trading diamonds. To escape persecution, many of them settled in Amsterdam, Antwerp and London. But the stone trade only really took off at the end of the 19th century, when the De Beers company began systematic mining in South Africa and then throughout the African continent (Congo, Angola, Namibia, Sierra Leone, Botswana). A historic change has taken place in the last ten years with the Kimberley Process: the United Nations intervened to put an end to diamond-funded wars and sponsored international control of rough diamond exports. - Citadelles & Mazenod - 2008