inerva’s Exo Tourbillon timepieces house one of the manufacture’s most highly celebrated complications, in which the balance wheel is suspended above the tourbillon cage. In the skeletonised version of this movement, the grace and sophistication of its intricate works are presented on full display.

This complication is reimagined in the Minerva Exo Tourbillon Skeleton Limited Edition 18, a timepiece that pays homage to the goddess Minerva’s connection to Ancient Rome. The watch presents a white and blue agate stone cameo in its open time-telling dial, while the tourbillon mechanism whirls with precision directly below. Meanwhile, a closer look at the details of the watch reveals its extensive symbolism.

The colour of Persian blue takes centre stage on the dial and the strap of the Minerva Exo Tourbillon Skeleton Limited Edition. Described as the colour of goddess Minerva’s eyes, the shade carries a long association with royalty across Europe and can often be found throughout royal palaces as a symbol of the nobility’s connection with divinities like Minerva.

The 44.8mm Minerva Exo Tourbillon Skeleton Limited Edition employs a cameo technique as its decorative highlight, taking inspiration from jewels of Antiquity crafted in similar style. Widely regarded as a highly delicate form of micro-sculpture, Roman emperors collected cameos, Augustus and Nero among the particularly avid collectors. These emperors’ interest set a trend in Ancient Rome among elites who wore these precious objects to indicate their power, wealth and refinement.

The cameo featured on the dial is made in two parts, blending cutting-edge technology with traditional craftsmanship in its creation. The base is made of polished and blocked blue agate stone.

Often called the “Stone of the Diplomat,” blue agate was believed to foster clear-headed communication essential to the maintenance of peace, also one of goddess Minerva’s key areas of governance. On top of this base, a white agate stone dial is first recessed and textured using a laser technique, then hand-engraved, before finally being completed by a painter specialising in miniature painting. The final result depicts the profile of Minerva, directly inspired by imagery found in historical Minerva advertising.

To complement this meaningful colourway, a deep Persian blue strap in alligator leather is finished with a matching folding clasp in 18K rose gold featuring a fine adjustment system and whose design, through numerous details, evokes the arrow of the goddess Minerva.

Minerva has further enhanced the exhibition of its patented Exo Tourbillon through extensive skeletonisation. With over 400 hand-polished inner bevels, this complex movement is reduced to a few lines that suspend the mechanism with elegance. The result is an airy arrangement full of negative space that recalls the art of cameo itself.

Around the tourbillon, the rose gold-coated frame is decorated with Roman frieze, a pattern that was used extensively in architecture and objects of art in Ancient Rome. At the top of its cage is the name “Minerva,” engraved and filled with blue lacquer that complements the symbolically significant colourway of the timepiece.

At the 4 o’clock position, a rose gold-coated plate engraved with “XVIII” indicates the limited edition of 18, itself a nod to the year 1858 when Minerva was founded.

The Minerva Exo Tourbillon Skeleton Limited Edition 18 marks the first time an Exo Tourbillon timepiece features Minerva’s recognisable fluted bezel – a signature of the manufacture since 1927. Here, the bezel is presented in 18K rose gold, matching the 18K rose gold case.

While any tourbillon is a feat of horological engineering, Minerva’s Exo Tourbillon Skeleton takes the historically significant mechanism into the 21st century. An evolution of the Exo Tourbillon that was first introduced in 2010 following a three-year development, the Minerva Exo Tourbillon Skeleton Limited Edition features the patented in-house Calibre M18.69, made up of 188 hand-decorated components.

“Exo” is Greek for “outside,” and in this instance the term refers to the balance wheel residing above the tourbillon cage. This distinctive solution not only minimises the diameter of the tourbillon cage and rotating escapement, but it also allows the balance wheel to be large enough to house 18 adjustment screws (regulating weights), which in turn adds mass to the unit. Greater weight, increased diameter and finer adjustability all improve precision. Increasing precision is rare in tourbillons, and it requires that the balance staff (the axle on which the balance wheel rotates) be mounted at tolerances as small as 5 microns (0.005 mm). This is accomplished by hand at the Minerva manufacture in Villeret.

The Minerva Exo Tourbillon Skeleton is not only a technical improvement, but its distinctive configuration allows the beating heart of the watch to be displayed in a mesmerising fashion. Remarkably, the tourbillon mechanism is anchored by a single-arm balance bridge. To align and secure a single-arm bridge to the tolerances required of this mechanism is a testament to the knowhow of Minerva’s master watchmakers.

The movement’s structure has been drastically reduced through extensive skeletonisation. Top-grade anglage with detailed inner-angle beveling – widely regarded as one of the most difficult aspects of movement finishing – and mirror-polishing complete the meticulous hand-finishing of the Calibre M18.69.

Echoing the historical inspiration of the Minerva Exo Tourbillon Limited Edition 18, the timepiece’s Persian blue presentation box was conceived for use as a jewellery box. In Antiquity, jewellery boxes were not only perceived as functional objects, but as symbols of refinement. Crafted from walnut wood, the box is adorned with the Roman frieze pattern on the outside and, on the inside, features a compartment with a blue watchmaker’s magnifying loupe.

TECHNICAL SPECIFICATIONS

Minerva Exo Tourbillon Skeleton Limited Edition – 18 pieces. Ident. 137551

• Movement: Minerva Manufacture Calibre M18.69
• Type of movement: Manufacture hand-finished manually wound movement
• One-minute patented Suspended Exo Tourbillon Skeleton
• Dimensions: Diameter = 41.95mm; height = 6.45mm
• Number of components: 188
• Number of rubies: 19
• Power Reserve: Approx. 50 hours
• Balance: Screw balance, diameter = 14.5 mm; moment of inertia = 59 mgcm²
• Frequency: 18,800 A/h (2.5 Hz)
• Hairspring: Hairspring with Phillips terminal curve
• Plate: Open-worked anthracite ruthenium-coated German-silver, stretched stripes on both sides, hand-chamfered edges
• Displays: Off-centered hours and minutes, small second at 6 o’clock Patented Exo
• Tourbillon (one revolution per minute to indicate the seconds) with one arm-bridge at 6 o’clock, mirror-polished Exo Tourbillon cage with the number 10 written in Sumerian
• Bridges: Open-worked anthracite ruthenium-coated German-silver, stretched stripes on both sides, hand-chamfered edges
• Going-train: Gold-coated, circular grained, chamfered, diamond hubs on both sides
• Barrel: Mirror-polished open-worked ratchet, circular-graining inside the mirrorpolished winding pawl shaped with the Minerva arrow
• Case: Rose gold 750/1000 (18 karats), polished case and Rose gold 750/1000 (18 karats) fluted bezel
• Crystal: Domed sapphire crystal with double anti-reflective coating.
• Back: Rose gold 750/1000 (18 karats), sapphire crystal case back with simple anti-reflective coating
• Dimensions: Diameter = 44.8mm; height = 15.1mm
• Water resistance: 3 bar (30m)
• Crown: Rose gold 750/1000 (18 karats), with Minerva Arrow
• Wristband: Deep Persian blue alligator leather strap, semi-matt finish, Roman friezes pattern on the lining and a rose gold 750/1000 (18 karats) triple folding clasp.
• Limited Edition: 18
• Certified by the Minerva Laboratory Test 500H