The unmounted oval stone is graded by the GIA as natural colour, VS2 and type IIa. It heads a sale strong in coloured diamonds.
An unmounted 8.63 ct oval fancy intense pink diamond is lot 644 in Sotheby's High Jewelry sale at the Mandarin Oriental, Geneva, on 11 November 2026. Its GIA report grades it natural colour, VS2 clarity and type IIa, and Sotheby's estimate is CHF 3,300,000 to 5,000,000.
The stone
The diamond is offered by Sotheby's as lot 644 in its High Jewelry sale in Geneva on 11 November 2026. According to the lot page it is an unmounted oval modified brilliant cut weighing 8.63 ct, with a GIA report dated 15 March 2024 grading it Fancy Intense Pink, natural colour, VS2 clarity and type IIa. Sotheby's estimate is CHF 3,300,000 to 5,000,000, about $4 million to $6 million, Rapaport reported. Because it is unmounted, a buyer can have it set as they choose.
What the grades mean
Coloured diamonds are graded by the strength of their colour as well as by its hue. The GIA scale runs from Faint and Light through Fancy, Fancy Intense and Fancy Vivid, with Fancy Deep and Fancy Dark for deeper tones, and each step up in intensity is rarer. Sotheby's notes that the colour of pink diamonds is thought to come from a distortion in the crystal lattice as the stone formed, not from trace elements as in many other coloured diamonds. Type IIa describes a diamond with almost no nitrogen, a group that makes up less than 2% of gem diamonds, according to the catalogue note.
Other coloured diamonds in the sale
The sale also includes an unmounted 8.11 ct cushion fancy pink diamond, graded VVS1 (lot 638, estimate CHF 1,500,000 to 2,500,000), and a Graff ring with a 2.88 ct pear-shaped fancy deep blue diamond (lot 643, estimate CHF 1,700,000 to 2,500,000). Sotheby's Royal & Noble Jewels sale follows in Geneva, and we covered its Devonshire Cartier opal tiara yesterday.
What drives the value of a coloured diamond
Hue, intensity, whether the colour is natural, clarity, cut and size all count, and a laboratory report is the starting point for any serious coloured stone. The same factors apply to the diamonds in family jewellery, on a smaller scale. Read our blue diamonds guide, browse our diamond jewellery, or see the four Cs explained. Every piece is different: send us a few photos and we will tell you what yours is worth, free and with no obligation.
More from Mozeris News
- The Devonshire Cartier Black Opal Tiara, Made With Opals From Australia, Heads to Sotheby's Geneva
- The Mellerio Orléans Tiara, Unseen Since 1957, Comes to Sotheby's Geneva
- The Bulgari Pink: a 24 ct Pink Diamond Heads to Christie's Geneva
- A 24.31 ct D Internally Flawless Diamond Ring and the £1.87 Million Result
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- View the sale at Sotheby's: High Jewelry, Geneva, 11 November 2026
- Lot 644: Superb unmounted fancy intense pink diamond, 8.63 ct, at Sotheby's
- Lot 638: Unmounted fancy pink diamond, 8.11 ct, at Sotheby's
- Lot 643: Graff fancy deep blue diamond and diamond ring, at Sotheby's
- Rapaport: Sotheby's to showcase $6M pink diamond at Geneva sale (28 Oct 2026)
- JCK: Sotheby's Geneva sale led by 8.63-ct. pink diamond
Facts as published by Sotheby's on its lot pages, and by Rapaport and JCK. Estimates are not results. Mozeris Fine Antiques is not connected with Sotheby's, Graff or anyone named. No photograph is used because no image issued for editorial use was available.
