Diamonds

Diamonds, long considered the most prized of gemstones, were first mined in India. Pliny may have mentioned them, although there is some debate as to the exact nature of the stone he referred to as Adamas; In 2005, Australia, Botswana, Russia and Canada ranked among the primary sources of gemstone diamond production.The British crown jewels contain the Cullinan Diamond, part of the largest gem-quality rough diamond ever found (1905), at 3,106.75 carats (621.35 g). Now popular in engagement rings, this usage dates back to the marriage of Maximilian I to Mary of Burgundy in 1477.