Europeans once believed that the cutting or alteration of a diamond would destroy its magical properties, but sometime after 1330AD, cutters in Venice learned how to shape and polish a diamond with an iron wheel coated with diamond dust to produce greater brilliance. The city then became the first centre for diamond trading. Over the next century, diamond traders, mainly Jews escaping from persecution, shifted to Bruges and Paris, and later to Antwerp. They marketed their diamonds to European jewellers, who began to set diamonds in jewels and royal regalia during the thirteenth and fourteenth centuries.
The diamonds came from Indian mines as well. Among the merchants who sailed east seeking to profit from the sale of diamonds and spices was the great Portuguese navigator Vasco da Gama. He was one of the first to sail via the Cape of Good Hope, hoping to avoid the Arab pirates who roved the Arabian Sea. He landed near Goa and this port became the Portuguese trading center in India, and a flourishing trade in diamonds developed from Goa to Lisbon and then on to Antwerp.
The discovery of diamonds in Brazil caused the collapse of the diamond market in 1725 although it was initially advertised that these diamonds came from India. India and Brazil were the main sources of diamonds up until 1851. Fifteen years later, a child of an African farmer picked up a white pebble that turned out to be a 21-carat diamond. This was followed soon afterwards by the discovery of another stone of 83-carats. These finds triggered a major diamond rush in South Africa and Rhodesia that later expanded in to mining for gold and coper. Deep volcanic pipes that were apparently an inexhaustible source of diamonds were then located, mined and factories started production.