Current weight: 59.60 carats
GIA colour grade: Fancy Vivid Pink
GIA clarity grade: Internally Flawless (IF)
Cut: Oval mixed cut
GIA classification: Type IIa (no nitrogen; highest purity classification)
Origin: De Beers mining, South Africa, 1999 (rough weight 132.5ct)
Cut and polished: Steinmetz Group, 20 months work (completed 2003)
Auction record: CHF 71,236,075 (approx. USD 71.2 million), Sotheby's Geneva, 4 April 2017
Buyer: Chow Tai Fook Enterprises, renamed CTF Pink Star
Sources: GIA Diamond Grading Report for the Pink Star; Sotheby's Geneva auction records; GIA research on the Pink Star in Gems & Gemology
Origin and cutting
The Pink Star was found in 1999 by De Beers in a South African mine as a 132.5-carat rough stone. It was purchased by Steinmetz Diamonds, a firm with exceptional experience in cutting major fancy colour diamonds, who spent approximately 20 months cutting and polishing it to the finished 59.60-carat oval mixed cut. The stone was unveiled in 2003 as the Steinmetz Pink and displayed publicly for the first time at the Smithsonian Institution in Washington DC (GIA Gems & Gemology research on the Pink Star; Sotheby's auction documentation).
GIA grading: Fancy Vivid Pink, Internally Flawless, Type IIa
The GIA graded the Pink Star as Fancy Vivid Pink, the highest saturation level on GIA's fancy colour grading scale for pink diamonds, and the grade that commands the highest premiums in the market. The stone is also graded Internally Flawless, the highest clarity grade GIA assigns to polished diamonds with no inclusions visible under 10× magnification. The combination of Fancy Vivid Pink colour, IF clarity, and 59.60-carat size, the largest Fancy Vivid Pink GIA has ever graded, makes it unique in the history of gem diamonds (GIA Diamond Grading Report for the Pink Star; GIA research documentation).
The stone is Type IIa, the rarest and chemically purest diamond type, with no detectable nitrogen or boron. The exceptional colour in a Type IIa stone is caused by structural deformation of the crystal lattice during formation, an intrinsic structural defect that selectively absorbs green and blue light and transmits red and pink. This structural origin of colour is different from the trace element origins of blue (boron) and yellow (nitrogen) diamond colours, and makes large natural pink diamonds extraordinarily rare (GIA Gems & Gemology, pink diamond colour origin research).
Auction history
The Pink Star was first offered at auction in November 2013 at Sotheby's Geneva, where it achieved a hammer price of CHF 76,000,000 (approximately USD 83 million), also a record at the time. However, the buyer (a diamond cutter) defaulted on the payment, and the stone reverted to Sotheby's. Sotheby's subsequently acquired the stone outright from Steinmetz and offered it again in April 2017, when it sold to Chow Tai Fook Enterprises for CHF 71,236,075 (Sotheby's Geneva auction records, 2013 and 2017; trade documentation of the 2013 default).
Primary sources
GIA Diamond Grading Report for the Pink Star. Gemological Institute of America. [Fancy Vivid Pink colour grade; Internally Flawless clarity; 59.60ct weight; oval mixed cut; Type IIa classification. GIA's grading of this stone as the largest Fancy Vivid Pink it has ever assessed is documented in GIA Gems & Gemology commentary.]
Sotheby's Geneva auction records. Sotheby's, Geneva. [April 4, 2017 hammer price: CHF 71,236,075 (approx. USD 71.2 million); buyer: Chow Tai Fook Enterprises; world record for gemstone at auction. November 2013 auction (CHF 76,000,000) and subsequent default also documented.]
GIA Gems & Gemology research on pink diamond colour origin. Gemological Institute of America. [Structural (lattice deformation) origin of pink colour in Type IIa diamonds; rarity of large natural pink diamonds.]