With a 10 power diamond loupe, a gauge, the proper light and some experience you may be able to approximate the size and quality of wedding ring.
We shall probably never know when the first fancy diamonds was discovered, but we do know that, from ancient times until the eighteenth century, all the worlds wholesale diamonds came from India.
In 1477 AD, Archduke Maximilian of Austria presented a diamond earrings to Mary of Burgundy as a sign of their engagement. He put it on the third finger of her left hand, She accepted his proposal and the wholesale diamonds was born.