Emeralds are green in color and belong to the beryl group, in which they are considered to be the most valuable stone. The color is green because they contain chromium. On the Mohs scale, emeralds have a hardness of 7.5-8. They are most commonly found in Colombia and Zambia, though they may also come from Russia, Pakistan and Brazil.
As Meghan Markle attends dress fittings, Princess Charlotte starts nursery, and not to mention a few million of us watching a little show called The Crown: 2018 looks set to be a rather royal year. On January 17, Sotheby's will hold their Of Royal and Noble Descent auction in New York, which features a replica set of the British Crown Jewels which were ordered on the occasion of Queen Elizabeth's Coronation. We check out five auctions of some of the most incredible royal jewellery pieces.