It is incredibly rare for Patek Philippe to do special commissions, even for its most important customers. So it follows that the appearance of a bespoke Patek Philippe at any auction is an occasion, but to have a custom Patek Philippe with possibly the third largest portrait diamond known makes for a truly rare event.

This extraordinary and fascinating wristwatch was created as a bespoke piece in 1991 to incorporate one of the world’s great natural treasures – one of the largest known lasque or portrait diamonds - ingeniously used for the watch’s crystal. The 13.43 carat flat transparent stone, probably an antique piece, was provided by the commissioning client to Patek Philippe in 1990 so that it could become the centrepiece of a wristwatch specially made to maximise its optical properties. The asymmetrical shape of the diamond inspired the design and making of this scintillating and truly exceptional watch delivered to the original client at Patek Philippe’s Geneva boutique in January 1994.

It’s clear that the design of the watch was created around the diamond – the abstract shape of the water-resistant case in 18k white gold made by Atelier Réunis follows the outline of the stone. This triangular shape also meant that Atelier Réunis also had make a custom 18k white gold bracelet to fit the case. So as to leave no doubt as to the importance of the diamond, its carat weight is permanently engraved for posterity on the interior of the caseback along with the unique reference 3843/1. A special sunburst blue coloured gold dial was also created by Stern Frères with asymmetrically positioned white gold indexes for the most pleasing visual effect.

Portrait-cut diamonds, otherwise known as “lasque” diamonds are an extremely rarefied group indeed and have always been very highly prized. They were almost solely the preserve of Royalty and were revered even amongst the world’s most fabled jewel collections. True portrait diamonds such as the present stone were cleaved from irregularly shaped octahedrons, polished flat on both sides, the top surface faceted at the very edges.

The portrait cut is one of the earliest with most examples dating from the 17th to the 19th centuries, originally intended to be the glazing for precious portrait miniatures, the use of a portrait stone for the glazing a of a watch is an inspired idea. In the words of jewellery historian Diana Scarisbrick “reflections from the facets light up the portrait, the highly polished limpid surface lets the subject shine through with far more eclat than crystal and also draws the eye towards it. Only the very clearest stones could obtain this magical effect”.

Measuring approximately 31.5 mm. x 25.6 mm and weighing 13.43 carats, the present stone is amongst the largest portrait diamonds known, the largest in the world measuring 40 mm. x 29 mm. It is also the biggest portrait diamond ever known to have been fitted to a watch. The following portrait diamonds are of comparable size to the present diamond:

- 25 carats, the historic “Tafelstein” enclosing a miniature of Emperor Alexander I of Russia, the largest known portrait diamond, 40 x 29 mm, now in The State Hermitage Museum, St. Petersburg.
- 22 carats, the Alexander I portrait diamond, 32 x 28 mm, now in The State Hermitage Museum, St. Petersburg.
- 13.43 carats, Patek Philippe case no. 2’914’662, the present diamond.
- 9.1 carats, “Empress Marie Louise”, formerly part of the French Crown Jewels, now Museum d’Histoire Naturelle, Paris.
- 32 x 32 mm, the Grand Duke Vladimir portrait diamond, now in a private collection.

Literature:
Portrait Jewels, Diana Scarisbrick, Thames & Hudson, chapter 5: The Portrait Diamond 1613-1906, 2011, p. 320-344.