The Caviar Tourbillon is a gem-set tourbillon wristwatch produced by Jacob & Co., the New York-founded luxury house established by Jacob Arabo in 1986. It represents one of the most technically demanding intersections of high jewellery and haute horlogerie in contemporary watchmaking: a timepiece whose dial, case, and bracelet are covered in an unbroken, seamless field of calibrated black diamonds set using invisible-setting techniques, while a mechanical tourbillon complication remains visible beneath the gem-set surface. The watch is the flagship expression of the broader Caviar collection, which takes its name from the visual analogy between the densely packed, lustrous black stones and the surface of fine caviar.

The Caviar Collection: Context and Concept

Jacob & Co. introduced the Caviar line as a vehicle for extreme gem-setting density applied to watchmaking. The central conceit is total chromatic immersion: rather than using gemstones as accent elements against a metal or enamel dial, the Caviar approach eliminates all visible metal from the dial plane and much of the case, replacing it with a continuous mosaic of black diamonds. The effect is one of deep, light-absorbing uniformity — a quality that distinguishes black diamond pavé from colourless or coloured stone settings, which scatter and return light. Black diamonds, being heavily included and graphitised, absorb rather than transmit light, producing a matte-to-satin surface that reads as a single coherent material rather than an assembly of individual stones.

The collection encompasses several references, including time-only and complication variants, but the Tourbillon is considered the apex expression, combining the setting complexity with the most mechanically prestigious of horological complications.

The Gemstones: Black Diamonds and Their Setting

Black diamonds used in gem-set watchmaking are almost universally natural diamonds whose colour arises from dense clouds of graphite inclusions, iron oxide clusters, or structural defects distributed throughout the crystal. Unlike fancy-colour diamonds, whose colour is assessed by GIA on a graded scale, black diamonds are evaluated primarily on the evenness and depth of their colour and the absence of surface fractures that would compromise setting integrity. Stones intended for calibrated invisible or tight pavé setting must be cut to precise, repeatable dimensions — typically in the range of 1 to 2 millimetres — with flat tables and consistent girdle thickness to allow the setter to achieve flush, gap-free coverage.

The invisible setting (serti invisible), developed in its modern form by Van Cleef & Arpels in the 1930s and subsequently refined by numerous houses and independent setters, involves cutting grooves into the pavilion of each stone so that it slides onto a network of fine metal rails concealed beneath the surface. No prongs or bezel walls are visible from above; the stones appear to float as a continuous plane. Applying this technique to a curved watch case — which introduces compound curvature across the dial, bezel, lugs, and bracelet — requires each stone to be individually calibrated to its specific position, since no two positions on a curved surface present identical geometry. This is the principal source of the extraordinary labour investment: the setting of a single Caviar Tourbillon may require several months of work by specialist gem-setters.

The total stone count across dial, bezel, case flanks, and bracelet in fully gem-set Caviar references runs to several hundred individual diamonds, with some configurations reported to exceed one thousand stones when the bracelet is included.

The Tourbillon Movement

A tourbillon is a regulating device invented by Abraham-Louis Breguet and patented in 1801, designed to counteract the effects of gravity on a watch movement's rate when held in a vertical position. In a tourbillon, the escapement and balance wheel are mounted within a rotating cage that completes one revolution per minute, averaging out positional errors. While the practical timekeeping benefit in a wristwatch — which changes orientation constantly — is debated among horologists, the tourbillon has become the pre-eminent symbol of mechanical watchmaking mastery, both for its visual drama and the precision required in its construction.

In the Caviar Tourbillon, the rotating cage is visible through an aperture in the gem-set dial, creating a deliberate visual counterpoint: the kinetic, mechanical spectacle of the tourbillon cage against the static, light-absorbing field of black diamonds surrounding it. Jacob & Co. develops and produces its tourbillon movements in-house, a capability the company has expanded significantly since establishing its manufacture operations. The movement architecture in Caviar Tourbillon references is typically skeletonised or partially open-worked to maximise the visual impact of the complication through the dial aperture.

Craftsmanship and Production

The production of a Caviar Tourbillon involves two parallel disciplines that must ultimately be reconciled in a single object: watchmaking and high jewellery gem-setting. The movement is assembled and regulated independently before the case is gem-set, since the vibration and mechanical stress of setting work could disturb a calibrated movement. The case components — typically in white gold or blackened gold to complement the black diamonds — are gem-set as separate elements and subsequently assembled around the completed movement.

The gem-setting workshop must work from a precise map of the case geometry, with each stone's position, orientation, and individual calibration recorded. Stones that fracture during setting — a not uncommon occurrence with black diamonds, which can be more brittle than colourless stones due to their inclusion density — must be replaced with a stone of identical dimensions, requiring the setter to re-open the adjacent rail system without disturbing surrounding stones. This vulnerability to loss and replacement is one reason why gem-set watches of this complexity are produced in very small series.

Market Position and Collecting Context

The Caviar Tourbillon occupies a specific niche within the high-jewellery watch market: it is not a dress watch in the traditional sense, nor a purely horological collector's piece, but rather an object that addresses collectors whose primary interest is the convergence of gem-setting artistry and mechanical complexity. Its natural comparators in the market are pieces from houses such as Graff, de Grisogono (whose de Grisogono Meccanico dG pursued similar all-black aesthetic ambitions), and Chopard's high-jewellery complications.

Retail pricing for Caviar Tourbillon references has historically placed them in the upper tier of the luxury watch market, reflecting both the cost of the black diamonds and the labour intensity of the setting work. The watches are produced in limited numbers and are typically available through Jacob & Co. boutiques and a small number of authorised retailers globally. At secondary market auction, gem-set tourbillons of this category tend to attract buyers from the Middle East, Asia, and the Americas — markets where the visual density of gem-setting is particularly valued alongside mechanical prestige.

It should be noted that the secondary market for heavily gem-set watches is generally less liquid than that for purely horological complications from traditional Swiss manufacture houses, as the pool of specialist buyers is narrower and condition assessment requires evaluation of both the movement and the integrity of the gem-setting — a combined expertise not universally available among watch auction specialists.

Significance in Gem-Set Watchmaking

The Caviar Tourbillon is significant as a demonstration of what calibrated invisible setting can achieve when applied to three-dimensionally complex surfaces at watchmaking scale. The miniaturisation of the setting work — stones of one to two millimetres set with sub-millimetre precision across compound curves — pushes the technique considerably beyond its application in flat jewellery surfaces. For gemmologists and jewellery historians, the piece documents the extension of a setting tradition originating in early twentieth-century Parisian haute joaillerie into the domain of precision mechanics, and illustrates the degree to which the boundaries between jewellery and horology have become genuinely permeable in contemporary luxury production.