The Princie Diamond is a 34.65-carat cushion-cut Fancy Intense pink diamond from the Golconda mines of southern India, certified by GIA as Type IIa with no fluorescence, and sold at Sotheby's New York on 16 April 2013 for thirty-nine million three hundred and twenty-three thousand seven hundred and fifty United States dollars. The result was, at that time, a record price per carat for any pink diamond sold at public auction and a record total price for any Golconda diamond. The stone is named after the teenage Maharaja of Baroda, called Prince by his family, on the occasion of a celebration at which his mother wore the stone in 1960.

Origin in Golconda

The diamond originated in the alluvial workings of the Kollur mines in the Krishna river basin of present-day Andhra Pradesh, the deposits historically referred to in the European trade as the Golconda mines. The Kollur deposits produced most of the great historic diamonds of the seventeenth and eighteenth centuries, including the Koh-i-Noor, the Hope, the Regent, the Orlov, and the Wittelsbach-Graff, and the term Golconda has come to be applied in the modern trade to any diamond identifiable through gemmological testing as having originated from these deposits. The defining test is the absence of nitrogen impurities at concentrations detectable by spectroscopy, the characteristic that makes a diamond Type IIa.

By the time the Princie surfaced in the historical record, in the seventeenth or early eighteenth century, the Kollur mines were already supplying the European royal courts through the Mughal-era Indian gem trade. The earliest documented owner of the diamond was the Nizam of Hyderabad, the ruler of one of the wealthiest princely states in the Indian subcontinent, in whose treasure the stone remained until the dissolution of the princely states in the 1948 to 1950 period. The Hyderabad treasure was assessed and divided in the years following Indian independence, and a number of significant diamonds, including the Princie, were dispersed onto the international market in the 1950s and early 1960s.

Acquisition by Van Cleef and Arpels and the naming

The diamond was offered for sale at Sotheby's London on 28 April 1960 and bought by Pierre Arpels of Van Cleef and Arpels for forty-six thousand pounds, the highest price paid for a diamond at auction up to that date. At a celebration held in Paris shortly afterward, the Maharani of Baroda was invited to be photographed with the diamond, and the firm gave the stone the nickname Princie in honour of her teenage son Yuvraj Sayajirao Gaekwad, the heir to the Baroda throne, who was known by the family pet name Prince. The name has stuck ever since.

The diamond passed from Van Cleef and Arpels through a number of private owners over the next half-century, with limited public visibility. Periodic appearances in private exhibitions and reference catalogues kept the diamond's existence in the trade record but did not generate a price-discovery moment in the public market until the 2013 sale at Sotheby's New York.

The 2013 Sotheby's sale

The Magnificent Jewels sale at Sotheby's New York on 16 April 2013 was held at the firm's York Avenue rooms, with the Princie offered as lot 357. The pre-sale estimate was thirty million to forty-two million United States dollars. The hammer price, including buyer's premium, was thirty-nine million three hundred and twenty-three thousand seven hundred and fifty dollars, slightly above the midpoint of the estimate. The result placed the Princie among the most valuable diamonds ever sold at auction at that time and set the per-carat record for any pink diamond sold publicly to that date.

The buyer's identity was not publicly disclosed at the sale. Subsequent reporting and litigation in the years following the sale produced public information about the buyer and about a dispute over the proceeds of the sale, which delayed full payment to the consignor and eventually involved the New York courts. The litigation concluded several years later, but the price discovery established in the saleroom is the public record that the trade now references.

The gemmological evidence

GIA certified the Princie as a 34.65-carat cushion-modified-brilliant cut diamond of Fancy Intense pink colour, with no observed fluorescence and a Type IIa classification. The Type IIa classification is established by infrared spectroscopy and confirms the absence of nitrogen impurities at detectable concentrations. The combination of Type IIa classification, Fancy Intense pink colour, and substantial size is rare; most Type IIa diamonds are colourless or near-colourless, and most fancy pink diamonds are smaller than two or three carats. A 34.65-carat Fancy Intense pink Type IIa is a combination of factors that occurs in the historical record only a handful of times.

The pink colour in Type IIa diamonds is understood to arise from plastic deformation of the crystal lattice during the diamond's residence in the Earth's mantle, rather than from a chemical impurity such as the boron that produces the blue colour in Type IIb stones. The deformation produces grain lines visible under polariscopy and a pink to brown body colour whose intensity varies with the degree of deformation. The Princie's Fancy Intense saturation places it well above the median of pink Type IIa diamonds and contributes substantially to the price.

Type IIa diamonds and the Golconda question

The trade increasingly conflates Type IIa classification with Golconda origin in the saleroom catalogue, although the two are not strictly equivalent. All Golconda diamonds tested in the modern era have been Type IIa, but Type IIa diamonds are also produced from a number of other deposits, including some Australian, South African, and Brazilian sources. A confident Golconda attribution requires both the Type IIa classification and a chain of provenance back to the Indian deposits, ideally documented through historical records that pre-date the opening of the major non-Indian deposits in the late nineteenth century.

The Princie carries both the Type IIa classification and the documented provenance back to the Hyderabad treasure, which is consistent with a Kollur origin and which the trade accepts as a Golconda attribution. The same standard of evidence is applied to the other major Golconda diamonds in the modern record.

The Princie's place in the pink-diamond record

The 2013 sale of the Princie sat in the middle of a decade-long sequence of headline pink-diamond auction results. The Graff Pink, a 24.78-carat Fancy Intense pink, sold at Sotheby's Geneva in 2010 for forty-six million dollars; the Pink Star, a 59.60-carat Fancy Vivid pink, sold at Sotheby's Hong Kong in 2017 for seventy-one and a half million dollars; the Pink Promise, a 14.93-carat Fancy Vivid pink, sold at Christie's Hong Kong in 2017 for thirty-two million dollars. Each result reset a per-carat or total-price benchmark, and the Princie's 2013 result is one of the data points the trade still references when modelling pink-diamond value.

The pattern across all of these sales is that pink diamonds of substantial size, high saturation, Type IIa classification, and documented provenance trade at multiples of the price commanded by colourless diamonds of equivalent weight and clarity. The Princie sits in the upper range of that distribution and remains, more than a decade after the sale, one of the touchstone reference points for valuing fine pink diamonds.

In the trade

For the modern coloured-diamond trade, the Princie is a reference price point and a reference standard. Buyers and consultants modelling the value of a fine pink diamond will compare proposed prices against the Princie sale, the Graff Pink sale, and the Pink Star sale, adjusting for size, colour grade, clarity, and provenance. The combination of a Golconda origin, a Type IIa classification, a Fancy Intense pink colour grade, and a three-hundred-year documented provenance is essentially impossible to replicate in a contemporary stone, which is why the Princie sits permanently above any benchmark a recently mined diamond can establish.

Further reading

• GIA Gems and Gemology — fancy coloured diamonds and Type IIa articles
• GIA — coloured diamond quality factors
• Sotheby's — Magnificent Jewels New York 16 April 2013 sale catalogue
• International Gem Society — historic and Golconda diamond reference