The Royal Canadian Mint is about to auction "The Ultimate," a one-of-a-kind, 1 kilogram platinum coin embellished with 462 ultra-rare pink diamonds from the world-famous Argyle diamond mine. Although it has a face value of CAD$2,500, the coin is expected to fetch as much as CAD$900,000 ($697,300) at the Heffel Fine Art Auction House in Toronto […]
