Diamonds

Diamonds 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;[8] 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.