Sartory-Billard SB10 Jumping Hour Blue Aventurine

Jumping Hour and Aventurine

Sartory-Billard SB10 Jumping Hour Blue Aventurine are watches that have chosen to forego the classic dial and hands. Time here takes on a completely different form – the hours instantly jump to the next digit every 60 minutes, while the minutes smoothly rotate around a central element. The result is a fascinating combination of two different rhythms: an instant jump and continuous motion.

The centerpiece of the watch is a blue aventurine glass cabochon, whose deep blue color is dotted with fine metallic inclusions. These create tiny points of reflection when light strikes them, resembling stars in the night sky. As the watch moves on the wrist, the way light hits the aventurine surface also changes. Some reflections stand out sharply, while others remain subtle and diffused. Thanks to the unique distribution of inclusions, each piece has a slightly different pattern, so no two watches are visually identical. And because the cabochon is placed directly on the case surface, it's not just for looking – you can actually touch it.

Even the time display itself is not ordinary on the SB10. At six o'clock, the current hour is displayed in a wide aperture using a sapphire disk. Its large numerals were designed specifically for Sartory-Billard by typographer Simon Schmidt and are almost twice as large as on traditional jumping hour watches. Reading the time is therefore surprisingly easy, even though the mechanism itself appears very unconventional.

Meanwhile, the minutes revolve around the aventurine cabochon. A second sapphire disk completes one full rotation in 60 minutes, and a red indicator on its perimeter shows the current minute. Around the central element is a ring with Super-LumiNova BGW9, which glows with a striking turquoise luminescence in the dark. This creates a luminous circle around the blue surface, resembling a tiny celestial phenomenon on the wrist.

Beneath the seemingly simple surface lies a Swiss automatic caliber La Joux-Perret G101A with a patented jumping hour module and a power reserve of 55 hours. Both the hour and minute disks are made of sapphire and are approximately 0.2 mm thick, so they almost disappear when looking at the watch, allowing the central cabochon to stand out.

The stainless steel case has a diameter of 39.5 mm, a lug-to-lug length of 44 mm, and a thickness of 11.5 mm. It combines brushed and polished surfaces and offers water resistance up to 80 meters. The Blue Aventurine can be fitted with a dark blue rubber or leather strap, or a steel bracelet with a combination of brushed and polished links and a quick-release system.

The SB10 is an important model for Sartory-Billard – it represents the brand's first complication and follows up on the experimental SB08 project from 2024. Its essence, however, is much simpler: to take the traditional way of displaying time, remove everything that is not essential, and create space for material and light instead of a classic dial. The Blue Aventurine variant perfectly embodies this idea. The deep blue, the tiny "stars" hidden in the material, the smoothly rotating minutes, and the instant jump of the hours create a watch that is not just a timepiece, but a striking object you'll want to look at even when you don't need to know the time.

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