Royal Oak Tourbillon Squelette, yellow gold

Skeletonising a Royal Oak is not a decorative exercise. Every bridge has to be recut until only the load-bearing metal remains, then chamfered, then engraved by hand — and the case has to hold that fragility with almost no solid dial surface to hide behind.

In yellow gold the effect changes completely. Steel skeletons read technical; this one reads warm, almost baroque, with the tapisserie replaced by open air and a printed sapphire chapter ring of Roman numerals floating over the movement.

The layout is more complete than a skeleton usually admits: small seconds at nine, a date sector at three, and the one-minute tourbillon at six, its cage visible from both sides through the sapphire back. The bridge work above it is engraved in a pattern that runs continuously across separate components — a detail only achievable when the parts are decorated in situ.

Yellow gold Royal Oak tourbillons appear in tiny numbers, and openworked examples in the metal are rarer still. This one arrived with its full set, and left through us.

It is in the Museum because it deserves the longer read. The write-up there covers the movement architecture and the provenance in full.