(NBC News) New York auction house is showing off a 118-carat white diamond that's the size of an egg.
The oval stone was highlighted at a Manhattan media event Wednesday. It will be auctioned in Hong Kong on Oct. 7 and has a pre-sale estimate of $28 million to $35 million.
Sotheby's calls it the greatest white diamond to be offered at auction in terms of size, quality, polish and color.
It was discovered in 2011 as a 299-carat rough diamond in an undisclosed southern African nation.
The current record for any white diamond is $26.7 million. That pear-shaped stone was over 101 carats. It was sold at Christie's in Geneva last spring.
The stone being auctioned next month is nearly 20 percent larger.
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