Arnold & Son Goes Early — and Goes Bold
Just ahead of Watches & Wonders 2026, Arnold & Son chose to release their most dramatic Ultrathin Tourbillon yet: a pair of watches dressed entirely in black onyx, with deep-polished stone on both the main dial and the hours-and-minutes sub-dial at 12 o'clock. It's a striking move from a brand that usually lets movement architecture speak louder than visual drama — and this time, both are shouting.
The Movement: Still the Most Impressive Thing Here
The in-house Calibre A&S8300 is nothing short of extraordinary. At just 2.97mm tall, it's one of the thinnest flying tourbillon movements ever built. To put that in perspective: most full dress watches have a movement thicker than this. Arnold & Son has been refining this calibre since 2015, and the 2022 update brought it to 100 hours of power reserve — which is exceptional for a hand-wound tourbillon. The movement is manually wound, which is the right choice at this level: no automatic rotor to distract from the architecture.
- Calibre: A&S8300, in-house, manually wound
- Height: 2.97mm
- Frequency: 21,600 vph (3 Hz)
- Power reserve: 100 hours
- Finishing: Radiating Côtes de Genève, snailed barrel ratchet wheels, polished blued screws
- Tourbillon: Flying (no bridge over the cage), visible at 6H front and back through sapphire crystals
Design: The Onyx Story
The novelty here is the stone itself. Onyx is a form of chalcedony — an agate family mineral — and Arnold & Son is using it in two distinct finishes that create exceptional contrast on the same material. The main disc is finely polished, giving it that deep, glossy, almost liquid black quality. The sub-dial at 12H is given a matte concave treatment — a first for the industry — which provides crisp legibility for the hours and minutes display while adding textural depth.
The case measures 41.5mm across and just 8.4mm thick including the domed sapphire crystal. Available in 18K 5N red gold and 950 platinum.
Exclusivity That Matters
This is limited to 8 pieces in each metal — 16 total globally. At that level, these watches will never appear on secondary market in any volume. For collectors who want genuine rarity backed by independent horological substance (rather than brand hype), this is the right formula.
Pricing
| Reference | Material | Price | Pieces |
|---|---|---|---|
| Ultrathin Tourbillon Onyx | 18K 5N Red Gold | CHF 74,600 | 8 |
| Ultrathin Tourbillon Onyx | 950 Platinum | TBC (~CHF 85,000+) | 8 |
Freddy's Verdict
Arnold & Son don't get enough credit. The A&S8300 at 2.97mm is a legitimate horological achievement, and 100 hours of power reserve in a hand-wound tourbillon at this level of finishing is genuinely impressive. The onyx dial is a bold but coherent design choice — it makes the watch visually arresting without being gimmicky. At CHF 74,600 for a genuinely in-house tourbillon in red gold, limited to 8 pieces, from an independent with deep English watchmaking heritage and serious technical credentials — this is exceptional value in the tourbillon space. Compare that to what a Patek or AP tourbillon would cost and you understand the proposition immediately.
Key Sources
- Monochrome Watches — Full Introducing
- T3 — Watches and Wonders Early Release Coverage
- Arnold & Son Official
