The Polar Star Diamond
The Polar Star Diamond
A 41.28-carat Type IIa cushion with documented eighteenth-century Russian provenance
The Polar Star is a 41.28-carat cushion-cut diamond of exceptional colour and clarity, with documented provenance reaching to the late eighteenth century in Imperial Russia. The stone is classified Type IIa — virtually free of nitrogen and other lattice impurities, the chemical type to which the world's most famous historical white diamonds belong — and it has appeared at major auctions in 1980 and again in 2002. It sits among the better-documented named diamonds of the European royal and imperial canon, though without the broader public recognition of the Hope, the Koh-i-Noor, or the Cullinan stones.
Provenance
The Polar Star's recorded history begins in the late eighteenth-century Russian court. The stone passed through the Yusupov family, one of the wealthiest noble houses of Imperial Russia, and is associated in the surviving accounts with Princess Tatiana Yusupova. The Yusupov collection — diamonds, coloured stones, and historic jewellery accumulated across several generations — was among the most significant private collections in pre-Revolutionary Russia. The Polar Star left Russia in the period of family emigration following the 1917 Revolution, with the family carrying portions of their collection abroad.
Subsequent ownership traced the stone through European jewellery dealers, with the Joseph Komkommer firm of Amsterdam holding the Polar Star at one stage. The diamond appeared at Christie's Geneva in 1980 and again in 2002, with extensive catalogue documentation accompanying both appearances. Buyer identity in the more recent sales has been treated as private, consistent with the practice for major historic stones.
Gemmological character
At 41.28 carats and Type IIa, the Polar Star is in the top fraction of one percent of historic diamonds by both size and chemical purity. The Type IIa classification means the stone contains less than the analytical detection threshold of nitrogen impurities, with the consequence that it transmits light across the visible spectrum without the yellow tinting that nitrogen-bearing (Type Ia) diamonds typically show. The result is exceptional transparency and a colour grade in the highest range — D, E, or F by GIA convention, with the specific grade depending on the laboratory examination at any given point in the stone's modern history.
The cushion cut, executed in the European style of the late eighteenth or early nineteenth century, gives the stone the soft-cornered rectangular silhouette and substantial depth characteristic of the period. Compared with modern cushion cuts engineered for maximum brilliance, the Polar Star carries the slower, deeper light return that period collectors and connoisseurs value as part of the stone's historical character.
Position among named diamonds
Within the canon of historically significant white diamonds, the Polar Star sits in a tier with stones such as the Wittelsbach (35.56 carats Type IIb fancy deep grayish-blue), the Beau Sancy (34.98 carats), and the Pasha of Egypt (38.19 carats), all carrying European court provenance with extensive documentation. The Polar Star's combination of size, chemical type, and Russian imperial provenance gives it a recognisable place in this group, recognised by the auction houses, Sotheby's and Christie's catalogue research departments, and historical-gem specialists.
In the trade
For Skyjems and other dealers tracking the historical-stone market, the Polar Star is a reference point in pricing and provenance research. Stones of comparable size, type, and provenance appear infrequently and trade at premium when they do; the Polar Star's documented chain of ownership and verified Type IIa classification give it a clear position in the landscape of investment-grade historic diamonds.