Our first live auction of 2025, the PHILLIPS Geneva Watch Auction: XXI, takes place on 10 - 11 May, at the Hotel President, at Quai Wilson 47, in central Geneva. The auction includes nearly 200 of the world's finest watches – and though we are loath to boast, we truly think it's one of the best catalogs we've ever put together. We'll be highlighting a number of the most interesting lots and stories featured in the sale over the next month, including the Cartier Portico Mystery Clock No. 3 detailed below.
– By Logan Baker
Every once in a while, something crosses the auction block that feels bigger than the sale itself. This spring, at the Phillips Geneva Watch Auction: XXI, one of those moments is about to happen.
Cartier’s Portico Mystery Clock No. 3 — a singular object of beauty, technical mastery, and historic importance — will be up for grabs.
Clocks like this don't just come around every day. In fact, they barely come around every generation.
The Magic of Cartier’s Mystery Clocks
Cartier’s mystery clocks are the stuff of legend.
Created during the golden age of Art Deco, they blend high jewelry, mechanical genius, and pure illusion. Maurice Coüet, the magician behind the movements, adapted an idea first pioneered by Jean Eugène Robert-Houdin in the 1830s: two crystal discs, invisibly notched and geared, carry the clock’s hands in apparent free flight.
When Cartier launched the first Model A Mystery Clock in 1912, nobody could explain exactly how it worked — not even Cartier’s own salespeople. That’s the level of mystery we’re talking about here.
Coüet’s Mystery Clocks pulled royalty, tycoons, and movie stars into Cartier’s orbit, offering something no one else could touch: a literal suspension of disbelief, crafted from gold, rock crystal, enamel, and diamonds.
Enter the Portico
Even within this elite category, the Portico clocks sit on a higher plane.
Cartier made just six of them between 1923 and 1925. Inspired by Asian temple gates, these clocks suspended the dial from the top of the structure, rather than hiding the movement below. It’s a small shift with a massive visual impact.
Where earlier mystery clocks felt delicate and ethereal, the Portico clocks brought a grand, architectural presence.
Charles Jacqueau, Cartier’s design wizard at the time, infused the Portico clocks with a Far Eastern flavor. Asian motifs — dragons, jade, Chinese guardian lions — became part of the clocks’ DNA.
Why Portico No. 3 Matters
Of the six Portico clocks, No. 3 is in a league of its own. Made in 1924, it’s one of only two with square columns (most have round ones). It’s also the only Portico clock with colored columns — two imposing shafts of rose quartz, banded with black enamel latticework at the base.
Flanking the columns are two carved “Fo” lion/dogs — traditional Chinese symbols of protection. The female guards the interior (your spirit); the male guards the structure (your physical domain).
Look up, and you’ll find the real showstopper: a 12-sided rock crystal dial, floating in mid-air. Rose-cut diamonds form the hands, shaped like a dragon — a nod to imperial China, where the dragon symbolized ultimate power and prosperity. Around the dial, a mother-of-pearl bezel sparkles with onyx and diamond-set Roman numerals, framed by seed pearls and black enamel.
And then there’s the “shou” symbol — 寿 — set above the dial in rose-cut diamonds. It means “longevity,” the ultimate wish for the lucky owner of this clock.
The workmanship here is transcendent. Even the winding key carries the movement number 946, perfectly matching the clock.
Portico No. 3 was exhibited at the 1925 Exposition des Arts Décoratifs in Paris — the very show that gave "Art Deco" its name. It’s appeared in landmark exhibitions and literature since then, from Gazette du Bon Ton in 1925 to Hans Nadelhoffer’s definitive Cartier: Jewelers Extraordinary.
Since 1988, it’s been quietly resting in a private collection, unseen by the public. Its reappearance at Phillips feels almost like the resurfacing of a lost masterpiece.
If you care about horology, jewelry, Art Deco, or just the history of objects, you should care about this sale. The last time a Portico clock crossed the block was in 1996 — almost 30 years ago.
And don’t kid yourself: once it’s gone, it’s probably gone for decades. Clocks like this tend to disappear into private collections for years and years.
Think about it: a mechanical and artistic marvel, created at the height of the Art Deco era, exhibited in 1925, resurfacing exactly 100 years later. You can’t script it better than that.
Cartier’s Portico Mystery Clock No. 3 is a once-in-a-century object that bridges art, craftsmanship, culture, and mystery. It represents everything that made Cartier the king of jewelers — and everything that still pulls collectors toward these rare, magical things today.
So if you find yourself in Geneva this May, stop by Phillips. Even if you’re not bidding, take a moment. Stand in front of Portico No. 3. Watch the dragon-shaped hands float through a face of carved rock crystal.
Feel the weight of a hundred years of history, still somehow lighter than air.
You can learn more, place a bid, and view the entire Geneva Watch Auction: XXI catalogue right here.
About Phillips In Association With Bacs & Russo
The team of specialists at PHILLIPS Watches is dedicated to an uncompromised approach to quality, transparency, and client service. Phillips in Association with Bacs & Russo holds the world record for the most successful watch auction, with its Geneva Watch Auction: XIV having realized $74.5 million in 2021. Over the course of 2021 and 2022, the company sold 100% of the watches offered, a first in the industry, resulting in the highest annual total in history across all the auction houses at $227 million.
About Logan Baker
Logan has spent the past decade reporting on every aspect of the watch business. He joined Phillips in Association with Bacs & Russo at the start of 2023 as the department's Senior Editorial Manager. He splits his time between New York and Geneva.
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