One of the world’s oldest stones, December’s birthstone, turquoise, plays an important role in ancient and modern culture. Treasured by groups ranging from the Egyptians to the Native Americans, turquoise is thought to be a healing gem. Whether you’re interested in turquoise for its protective properties or simply its rich blue color, there are plenty of beautiful options in Sotheby’s upcoming jewels sales. Click ahead to discover turquoise lots from upcoming sales, including stunning pieces from the collection of Barbara and Frank Sinatra. –Stephanie Sporn
