Diamond prices keep breaking records.
The latest is a 118-carat, flawless D-diamond that was auctioned off by Sotheby's on Monday for $30.6 million. That beat the previous auction-price record for a white diamond of $26.74 million, paid for the "Winston Legacy" this spring at Christie's.
The 118-carat diamond, about the size of an egg, sold for the low end of its price estimate of $28 million to $38 million. Sotheby's declined to comment on the buyer or the buyer's nationality.
(Read more: Investing in diamonds? Good luck getting prices)