There is a moment, when you hold a gemset Richard Mille close to the light, that the boundary between jewellery and engineering dissolves completely. Stones do not sit atop the case. They become the case. That shift in thinking represents something genuinely new in the history of gem-set watchmaking, and understanding it requires a proper look at the craft from its foundations.
The Craft Behind the Sparkle
Gemsetting in watchmaking draws from a vocabulary developed over centuries of fine jewellery. The most widespread technique is bead or pavé setting, where a craftsman drills individual cavities into the metal, inserts the stone, and raises tiny beads of metal around it to hold it in place. The result, when executed by a skilled hand, is a continuous surface of light with almost no visible metal between stones. Snow setting refines this further, mixing stones of varying sizes between 0.5 and 1.6 millimetres to create what reads as an apparently random scatter across the surface, though in practice each placement demands precise compositional thinking.
Invisible setting stands at the opposite end of technical difficulty. Each stone undergoes preparation by a lapidary who cuts a horizontal groove into its base; the gems slide onto custom-machined rails inside the setting with no visible metal holding them at all. The stones appear to float, suspended by invisible forces. Because the technique allows no adjustment once the stones lock into place, every element must be engineered to exact tolerances before the first gem ever enters the setting. Bezel and prong settings round out the standard toolkit, each offering different trade-offs between stone exposure, security, and visual weight.
Advantages, Limitations, Trade-offs
Pavé and bead settings offer a gemsetter the greatest creative freedom. The technique scales well across complex three-dimensional surfaces, adapts to curved architectures, and allows for corrections during execution. Its limitation is visibility of the metal structure at close inspection. Snow setting provides the most expressive freedom of the techniques, though the deliberate variation in stone size demands that a gemsetter possess a calibrated aesthetic eye alongside technical precision.
Invisible setting produces the most dramatic jewellery effect, but it concentrates enormous risk into the preparation phase. Any error in the rail geometry or the groove cut into the stone means the entire composition fails. It also limits the shapes and surface topographies that accept the technique effectively, which matters greatly in a world where case geometry is as assertive as it is at Richard Mille. Prong setting, by contrast, maximises light entry into the stone from multiple angles, though the metal elements remain visible and can interrupt the continuity of a set surface.
The Richard Mille Problem
Richard Mille cases do not look like anything else in watchmaking, and that visual originality creates immediate headaches for gemsetters. The tonneau form, the arched casebands, the exposed pillar structures: these surfaces resist the flat-plane assumptions that underpin most classical setting work. A gemsetter trained on conventional gold cases must essentially rethink their spatial logic from the start.
The harder challenge, though, is material. Carbon TPT® is composed of hundreds of layers of carbon filaments, each no thicker than 30 microns, impregnated with resin and heated under pressure to 120°C. It is extraordinarily light and stiff, which is why Richard Mille loves it. It is also, for a gemsetter, a near-nightmare. Standard setting gravers and tools bite into gold predictably. Carbon TPT® responds differently to every cut, and the composite structure means that raising a bead of metal is not an option. There is no metal to raise.
Richard Mille’s response to this problem, developed collaboratively with ProArt, the brand’s case manufacturer, was to use diamond-head CNC milling cutters to puncture the Carbon TPT® and create the individual cavities. Gold prongs are then manufactured separately, hand-polished, and inserted into those cavities individually. Setting even the front bezel of one of these watches takes roughly three days from preparation to final stage, before accounting for the stones themselves. On a difficulty scale from one to ten, those who work the material without hesitation rate the process a nine.
Ceramic presented its own set of complications. The solution came from Cécile Guenat, Head of Design and Development at Richard Mille and a graduate of the Geneva University of Art and Design, who adapted a direct microblasting process to prepare ceramic surfaces for setting. Gold prongs for ceramic-cased pieces are individually manufactured and polished before embedding into the prepared surface, and 0.25mm diamonds set in red gold prongs cover cases where once the hardness of the material made any setting seem implausible. For sapphire, the brand turned to laser cutting rather than mechanical milling, carving cavities with margins of error measured in single microns.
Architecture Goes Inside the Movement
Perhaps the most radical expression of Richard Mille‘s gemsetting ambition came not on the exterior of the watch but inside it. The RM 018 Tourbillon Boucheron, released in 2008, used stone to fabricate actual gear wheels within the movement, incorporating tiger-eye, jasper, black onyx and diamonds. Each wheel received a sunray pattern profile worked entirely by hand in Boucheron’s Place Vendôme atelier. The development took over four years. The following year, the RM 019 Tourbillon took the idea further still, carving the movement baseplate itself from black onyx. Stones had moved from decoration to structural component.
A Workshop, a Vision
The launch of Richard Mille’s in-house gemsetting workshop in June 2019 formalised what had been building for over a decade and a half. Since the first RM 007 appeared in 2005, the brand had been accumulating knowledge and expanding what the craft could absorb technically. The RM HJ-01 haute joaillerie collection, bringing ruby, blue sapphire, violet sapphire and emerald together across four unique tonneau pieces with bezel, bead and snow settings, represents the current culmination of that journey. Stones here are not an afterthought applied to a finished case design. They are constitutive elements, on par with the calibre architecture itself. In the long history of the gemsetter’s art, that is a genuinely new position to occupy.
