Chronometry Ultrathin Tourbillon Red Gold Onyx LTD 8

A Warm Expression of Depth and Chronometry

At the crossroads of refined minimalism and high-precision watchmaking, Arnold & Son unveils the Ultrathin Tourbillon Red Gold Onyx—a timepiece that transforms the flying tourbillon into an expression of depth, warmth, and restrained elegance.

Housed in a 41.5mm case crafted from 18-carat 5N red gold, this limited edition of 8 pieces embodies the Maison’s chronometric heritage with contemporary sophistication. Its broad dial fully exploits the intense black of onyx, creating a powerful contrast with the glow of red gold and allowing the regulating organ at 6 o’clock to emerge with striking clarity.

Mechanical Refinement: The A&S8300 Calibre

At the heart of the Ultrathin Tourbillon Red Gold Onyx beats the Calibre A&S8300, a manual-winding Manufacture movement developed by Arnold & Son. Measuring just 2.97mm thick, this ultra-thin calibre gives the watch its elegant 8.40mm profile while preserving the technical authority expected of a haute horlogerie creation.

Operating at a frequency of 3 Hz and offering a remarkable 100-hour power reserve, the A&S8300 calibre reflects the Maison’s pursuit of chronometric excellence. Visible through the sapphire crystal caseback, it reveals refined finishing including radiating Côtes de Genève, chamfering, snailing on the two-barrel ratchet wheels, and polished, blued, and chamfered screws.

The Flying Tourbillon: A Regulating Organ in Motion

Positioned at 6 o’clock, the large flying tourbillon becomes the visual and mechanical centre of the composition. Its delicate cage opens through the onyx dial, revealing the hand-bevelled architecture of a mechanism conceived to combine precision, lightness, and visual poetry.

Its symbolic details recall Arnold & Son’s maritime heritage: a stylised sextant evokes John Arnold’s role in advancing the calculation of longitude with his marine chronometers, while the anchor-shaped counterweight serves as a reference for reading the seconds as the cage completes its one-minute rotation.

A Dial of Black Onyx: Mystery, Contrast and Warmth

The identity of the Ultrathin Tourbillon Red Gold Onyx is expressed through the refined duality of its stone dial. The main dial is fashioned from a finely polished disc of genuine black onyx, selected for its intense, enigmatic depth and long-standing association with strength, power, and discernment.

The concave hours-and-minutes sub-dial is also crafted from black onyx, but treated with a matt satin finish—a first in watchmaking according to the Maison. This subtle contrast between polished and matt stone brings texture, depth, and architectural balance to the display, while the surrounding red gold case adds warmth and precious intensity.