‘Perfect’ 100-carat diamond goes under Sotheby's hammer

[caption id="attachment_820447" align="aligncenter" width="600"] The Ultimate Emerald-Cut Diamond held by a Sotheby’s employee.[/caption] An internally "flawless” 100-carat emerald-cut diamond that will go under Sotheby's hammer in New York on Tuesday is expected to fetch up to $25 million. The gem, discovered...