Magnificent diamond

The cushion brilliant-cut diamond weighing 70.33 carats, mounted as a ring, size 51^1/2.

Accompanied by GIA report no. 5151832545, stating that the diamond weighing 70.33 carats, measuring 29.50 x 22.56 x 13.95 mm, is D colour, Flawless, together with a classification letter stating that the diamond is type IIa. Stamped PT950 for platinum. For further information on the diamond, please refer to the GIA report. Minor signs of wear to the metal. Condition as new. Gross weight approximately 14 grams.
"In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Please note that colour, clarity and weight of gemstones are statements of opinion only and not statements of fact by Sotheby's. We do not guarantee, and are not responsible for any certificate from a gemological laboratory that may accompany the property. We do not guarantee that watches are in working order. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective, qualified opinion. Prospective buyers should also refer to refer to any Important Notices regarding this sale, which are printed in the Sale Catalogue, in particular to the Notice regarding the treatment and condition of gemstones and to the Notice regarding import of Burmese jadeite and rubies into the US.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING A LOT, ALL LOTS ARE OFFERED AND SOLD "AS IS" IN ACCORDANCE WITH THE CONDITIONS OF BUSINESS PRINTED IN THE SALE CATALOGUE."

Introduced at the beginning of the 20th century, the modern cushion-cut derives from ancient cushion-cut diamonds, sometimes referred to as 'old mine' cuts. The most famous predecessor of today’s cushion-cut is the 140.64 carat Regent diamond, formerly part of the French Crown Jewels, currently conserved at the Louvre, Paris. Discovered in Golconda, India in 1698 and sent to England to be cut between 1704 and 1706, the Regent became one of the first important examples of cushion-shaped diamonds. Probably developed in the 17^th century, this cut slowly replaced the former dominant style of faceting, known as step-cutting. This experiment with perpendicular cuts, as opposed to horizontal ones, ultimately led to the development of the true round brilliant, in the late 19^th century.

This magnificent 70.33 carat cushion brilliant diamond has not only received the highest colour and clarity grade from the GIA for white diamonds, D Colour, Flawless Clarity, but has also been found to be part of the rare Type IIa subgroup. Stones of this group, which comprise less than 2% of all gem diamonds, are chemically the purest of all diamond crystals and often have extraordinary optical transparency.