Biggest white diamond to be auctioned, egg-shaped 'The Rock', fetches over $21 million in auction

Geneva: Christie's says 'The Rock,' an egg-sized white diamond billed as the largest of its kind to go up for auction, sold on Wednesday (May 11) for more than 21.6 million Swiss francs (USD21.75 million), including fees - though at the low end of the expected range.

The 228-carat pear-shaped G-Color stone, with its platinum pendant mounting, has a gross weight of 61.3 grams and dimensions of 5.4 centimeters by 3.1 centimeters (2.1 inches by 1.2 inches), making it about the size of a medium hen's egg. G-Color is not the highest grade, but fourth on the letter rung below the top-grade D-Color diamonds.

An unspecified private buyer acquired The Rock, for which the pre-auction estimate was between 19 million and 30 million francs.
Max Fawcett, head of jewelry at Christie's Geneva, hailed a successful sale in "uncharted territory" for a stone of its kind.

Also going under the hammer on Wednesday was the "Red Cross" diamond, a 205.1-carat fancy yellow stone, which fetched nearly 14.2 million francs, double the pre-sale estimate. The diamond was cut from a rough stone unearthed from South Africa's Griqualand mines in the early 20th century and went up for auction for the first time in 1918. Fawcett testified to a "huge amount of interest" in the Red Cross diamond, saying that an unspecified "7-figure sum" from the proceeds of the sale to an unspecified private buyer would be donated to the International Red Cross Movement, the Geneva-based humanitarian aid group.