RAPAPORT... Sotheby’s will offer a yellow diamond weighing more than 300 carats at its upcoming New York auction, where it is expected to fetch more than $15 million.The pear-shaped, 303.10-carat, fancy-deep-brownish-yellow stone is one of the largest polished diamonds in the world. It is also the largest flawless or internally flawless diamond ever graded by the Gemological Institute of America (...
