A Coveted Cartier Mystery Clock Could Fetch Over $6 Million at Auction

A marvel of high horology could soon be yours.

A coveted Cartier Portico Mystery Clock will be auctioned off at Sotheby’s Important Watches sale in Switzerland this November, with the rarity expected to fetch between 3 million and 5 million Swiss francs (about $3.7 million to $6.2 million at the current exchange rate).

Cartier horologist Maurice Couët created the Parisian label’s first mystery clock, the Model A, in 1912, drawing inspiration from a magical design Jean-Eugène Robert-Houdin unveiled almost a century prior. The French illusionist-turned-watchmaker presented the world’s first mystery clock around 1831, equipping it with mechanisms that tricked the eye like something in his act.

Cartier’s mystery clocks all have “floating” hands at the center of a translucent dial. With no visible connection to the movement, the hands appear to be driven by a mysterious, unknown force rather than, say, a gear train. For the Model A, Couët hid most of the mechanism in the base. With the newer Portico model, Couët managed to conceal the whole mechanism in the dial in a true feat of horological ingenuity. (The maison later followed up with mystery watches, shrinking the illusion and making the execution all the more impressive.)

Cartier’s then-leading designer Charles Jacqueau gave the Portico a fresh aesthetic inspired by Oriental art, adding temple-like columns and other Asian architectural details. The clocks also exude the elegant Art Deco feel that Cartier developed in that era, with materials such as rock crystal, onyx, mother-of-pearl, jade, and gemstones adding a sense of luxury.

Cartier produced only six Portico models between 1923 and 1925, rendering each one exceptionally rare. This particular Portico was made in 1923, making it one of, if not the, earliest examples. It has been in the same family since 1978 and will be the first of the six to appear at auction in almost half a century.

“This is a landmark moment in the world of horology and in collectors’ circles, given how extraordinarily rare Cartier Portico Mystery Clocks are at auction,” Sam Hines, Sotheby’s global chairman of watches, said in a statement. “To present this 1923 model, one of the earliest in the six-strong series ever created, for the first time in nearly fifty years, is not only a privilege but also an event of remarkable importance, especially to international collectors.”

Sotheby’s Important Watches auction will take place in Geneva, Switzerland, on November 9.