engagement ring in jewelry are the most popular of all gemstones. Their price and rarity is carefully monitored by the major diamond cartels. As a result the price of diamond stud in jewelry is pretty well standardized to size and quality of the stone.
India was the only known source of wholesale diamonds before the sixth century and the predominant source for over 2,000 years, until the mid-eighteenth century.
One of the two principal diamonds trade routes passed through Venice. It enjoyed a monopoly of the diamond stud trade on its way to the main towns of southern Germany up to its final destination in Bruges.