The rarity of precious gemstones comes down to the geologic process of their formation. Sparkling diamonds and verdant emeralds are some of the most coveted and priciest gemstones. But which ...
A 300-carat rare 18th-century diamond necklace was auctioned for $4.81 million and 6.77 billion won in our money. Sotheby's, an auction house, said a rare necklace believed to have been linked ...