The Excalibur Diamond refers to fully gem-set variants within Roger Dubuis's flagship Excalibur collection — a line of watches that has, since its introduction in the early 2000s, come to represent one of the most visually assertive intersections of haute horlogerie and high jewellery in the contemporary watch market. Characterised by skeletonised movements, bold circular architecture, and the lavish application of baguette-cut diamonds and coloured gemstones across bezels, cases, dials, and bracelets, these timepieces are aimed at collectors who regard technical complication and gemological spectacle as inseparable virtues. Roger Dubuis, founded in Geneva in 1995 by watchmaker Roger Dubuis and businessman Carlos Dias, became part of the Richemont group in 2008 and holds the distinction of having its entire production certified by the Poinçon de Genève — the Geneva Seal — one of the most demanding quality marks in Swiss watchmaking.

The Excalibur Collection: Architectural Context

The Excalibur line takes its name and visual language from Arthurian mythology, but its design vocabulary is resolutely contemporary: twelve pointed indices arranged like the spokes of a wheel, an open-worked dial that exposes the movement beneath, and a round case of substantial diameter — typically 42 mm or 45 mm — that wears with considerable presence on the wrist. The collection encompasses a wide range of complications, from three-hand automatics to flying tourbillons, minute repeaters, and multi-axis tourbillon constructions. It is within this framework that the gem-set variants — the Excalibur Diamond models — are positioned at the apex of the range.

Gem-set Excalibur references are typically built on the same movement architecture as their non-jewelled counterparts, meaning the gemstones are applied to the case, bezel, bracelet, and sometimes the bridges of the movement itself, without compromising the mechanical specification. This approach distinguishes them from purely decorative jewelled watches: the wearer acquires both a certified haute horlogerie movement and a piece of jewellery in a single object.

Gemstone Setting: Baguette Diamonds and Beyond

The defining gemological feature of the Excalibur Diamond models is the extensive use of baguette-cut diamonds. The baguette — a step-cut rectangle with a long table facet and comparatively few facets overall — is favoured in high-jewellery watchmaking for its ability to create continuous, uninterrupted lines of brilliance across curved surfaces. Setting baguettes around a circular bezel or along a bracelet link requires each stone to be individually calibrated, a labour-intensive process that demands close collaboration between the watchmaker and the stone-setter. On Excalibur Diamond references, baguettes are commonly channel-set or grain-set in rows that follow the contours of the case, producing a surface that reads as a continuous field of light rather than a collection of individual stones.

Beyond white diamonds, certain Excalibur Diamond variants incorporate coloured gemstones — sapphires, rubies, and emeralds have all appeared in the collection — either as accent stones within an otherwise diamond-set composition or as the primary gemological statement. The use of coloured stones in high-jewellery watches follows the same quality criteria applied in fine jewellery: saturation, tone, and freedom from visible inclusions are paramount, since stones are viewed at close range and under varied lighting conditions throughout the day.

Total diamond weights across fully set Excalibur references can reach several carats, with the precise count varying by reference. The stones used are typically of high colour and clarity grades, consistent with the expectations of the haute joaillerie market segment.

Notable References: Spider and Diabolus in Machina

Two references within the Excalibur family have attracted particular attention in the context of gem-setting. The Excalibur Spider — named for the web-like architecture of its skeletonised movement, in which the bridges radiate outward from a central hub — has been produced in gem-set versions featuring diamonds on the bezel, lugs, and bracelet, with the movement itself visible through the open dial. The visual effect is one of considerable complexity: faceted stone surfaces surrounding an equally intricate mechanical interior.

The Excalibur Diabolus in Machina, introduced in more recent years, takes the skeletonisation further still, incorporating a double flying tourbillon — two tourbillon cages rotating on separate axes — within a case that has been offered in gem-set configurations. The Diabolus in Machina represents the technical summit of the Excalibur range, and gem-set versions of it occupy a correspondingly rarefied position in terms of both price and rarity.

The Geneva Seal and Its Gemmological Implications

The Poinçon de Genève, or Geneva Seal, is a quality certification administered by the Republic and Canton of Geneva. Its criteria cover movement finishing, component tolerances, and — critically for gem-set pieces — the quality and execution of stone setting. A movement bearing the Geneva Seal must have been both made and cased in the Canton of Geneva, and the certification process includes inspection of the setting work on jewelled references. This means that Excalibur Diamond watches carrying the Seal have had their gemstone setting evaluated as part of the same quality process that certifies the movement's finishing. For the collector, this provides a degree of assurance that is unusual in the broader luxury watch market, where gem-set pieces are not always subject to the same rigorous independent scrutiny as their movements.

Roger Dubuis's commitment to universal Geneva Seal certification across its production — a claim few manufactures can make — gives the gem-set Excalibur models a documentary credibility that reinforces their position in the high-jewellery watch segment.

Market Position and Collector Context

Gem-set Excalibur references occupy the upper tier of the Roger Dubuis price range, which itself sits at the higher end of the Swiss independent manufacture market. They are typically produced in limited numbers, often as boutique exclusives or as part of defined limited editions, and are sold through Roger Dubuis's own retail network and authorised partners. The target collector is one who is comfortable acquiring a watch as both a horological instrument and a jewellery object — a profile that has grown in significance as the boundaries between watchmaking and jewellery have become increasingly permeable at the top of the market.

In the secondary market, gem-set complications from recognised manufactures have historically shown more variable performance than their non-jewelled equivalents, partly because the pool of buyers who value both the mechanical and the gemological components simultaneously is narrower than the pool for either category alone. Excalibur Diamond references are, however, supported by the broader recognition of the Roger Dubuis brand within the Richemont portfolio and by the documentation that Geneva Seal certification provides.

Specialist publications including WatchTime and Revolution have covered the Excalibur Diamond models in depth, and the collection has been a consistent presence at Watches and Wonders Geneva (formerly SIHH), the annual trade event at which Richemont manufactures present new references to the press and retail community.

Further Reading

• Gems & Gemology — GIA's peer-reviewed journal covering gemstone quality and identification
• GIA: Diamond Quality Factors