HM Pietersite

The watch features a star-shaped arrangement of seven bridges, radiating from the center like a nebula, giving it both structural integrity and visual depth.

The movement is laid out with four lines of symmetry, aligning the barrels, balance, and small seconds for a harmonious aesthetic.

Technical Excellence: A&S5201 Calibre

Dual barrels provide an impressive 90-hour power reserve.

Components are arranged in a kinematic chain around the edge, enhancing both function and form.

The crown mechanism is inverted and placed on the case-back side for symmetry with the first wheel at 9 o’clock.

Aesthetic Details

The lower levels of the movement are treated with a rich blue PVD, contrasted by palladium-finished bridges and components.

Includes horizontal satin brushing on the dial side and Arnold & Son’s signature ‘Rayons de la Gloire’ motif on the reverse.

The 40 mm diameter and 9.10 mm thickness ensure elegance on the wrist.

Strap & Bracelet Options

Available with a blue alligator leather or rubber strap.

Also offered with a three-link steel bracelet that highlights the watch’s symmetry and skeletonized beauty.

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Arnold & Son unveils the Perpetual Moon 41.5 Cliff Grey Edition, a poetic tribute to the cliffs of Cornwall and the legacy of John Arnold, the renowned marine chronometer-maker. This limited edition of 28 pieces in 18-carat red gold reflects the brand’s deep connection to celestial navigation and English heritage.

The dial is adorned with the exclusive Stellar Rays motif, a textured pattern that plays with light through layered transparent lacquer. Its Cliff Grey tone evokes the misty British coastline, while the moon phase display—among the largest in watchmaking—glows in mother-of-pearl enhanced with Super-LumiNova. Set against a midnight-blue sky, the moon is surrounded by hand-painted constellations, Ursa Major and Cassiopeia, symbols of guidance and exploration.

The case, measuring 41.5 mm in diameter, is sculpted with refined lugs and a slim bezel that opens up the dial to its full celestial display. On the reverse, a secondary moon-phase indicator allows for precise adjustment of the moon’s age.

Inside, the manually wound A&S1512 calibre offers a 90-hour power reserve and tracks lunar cycles with remarkable precision. So accurate is its mechanism that it would take 122 years of continuous operation to accumulate a single day’s deviation from the actual lunar cycle.

Crafted entirely in-house in La Chaux-de-Fonds, the movement is finished with Geneva stripes, blued screws, and circular graining. The watch is completed with a warm grey alligator leather strap and a matching red gold pin buckle.

The Cliff Grey Edition is a refined expression of Arnold & Son’s dedication to craftsmanship, astronomy, and timeless design.

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Arnold & Son introduces a radiant new chapter in feminine watchmaking with the Perpetual Moon 38 White Gold Aventurine Edition. Limited to just 18 pieces, this poetic timepiece captures the magic of moonlight and the brilliance of the stars.

Encased in 18-carat white gold, the 38 mm watch features a dial crafted from blue aventurine glass, evoking a starlit sky. The bezel, lugs, and crown are adorned with 80 brilliant-cut diamonds, while 12 marquise-cut diamonds mark the hours. At its heart lies a mother-of-pearl moon disc, framed by hand-painted constellations of Ursa Major and Cassiopeia, enhanced with Super-LumiNova for a celestial glow.

Powered by the A&S1612 manual-winding movement, the watch offers a 90-hour power reserve and an astronomically precise moon phase complication that deviates by only one day every 122 years.

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Mystical, untamed and dazzling, the Perpetual Moon 41.5 Red Gold “Year of the Horse” follows in the footsteps of Arnold & Son’s Chinese zodiac collections. In the year spanning 2026 and 2027, the Fire Horse will set the astrological tone for connoisseurs of watchmaking and métiers d’art. To celebrate this flamboyant sign, Arnold & Son presents a limited edition of eight pieces, housed in 41.5-mm red gold cases. And while the noble animal is ever alert, it is at night that the full extent of its fiery, mysterious and incandescent nature is revealed.

A horse rears on a hill top – a commanding silhouette carved out against a star-studded sky, surrounded by the sparks of a metaphorical fire. This is Arnold & Son’s interpretation of the Fire Horse, the sign that will succeed the Wood Snake on 17 February 2026. For the sixth consecutive year, Arnold & Son is back in the saddle, drawing on the full breadth of its artistic savoir-faire. Miniature painting, three-dimensional engraving, fine stonework and the refined finishing of an astronomical moon-phase calibre: the Perpetual Moon 41.5 Red Gold “Year of the Horse” tells a tale of excellence, symbolism and vital energy.

An ardent design
Behind the expressive power of the scene, lies all of Arnold & Son’s creativity and mastery. The horse, in 18-carat red gold appliqué, is hand engraved. From hooves to mane, every muscle seems to ripple with energy. The black aventurine sky shimmers like a vast, celestial expanse, where distant stars mingle with mountainous reliefs and shadowy woodland undergrowth.

In the horse’s wake, hand-painted golden dust evokes a trail of sparks that ignite one after the other as the animal passes. These glowing flashes reflect its inner fire and untamed spirit. Touches of red and yellow Super-LumiNova, diffusing the same nocturnal shades, transform the scene as the light dims. Under the radiant mother-of-pearl moon, the horse’s majestic silhouette stands out, while the embers smoulder with new intensity. Not far away, the constellations of Cassiopeia and Ursa Major take shape on the lunar disc, completing this dual-faced, dual-display dial.

A noble pedigree
On the case back, a secondary moon-phase display enables fast, accurate setting of the lunar age. The heart of the Perpetual Moon 41.5 Red Gold “Year of the Horse”, the manual winding A&S1512 calibre, follows the lunar cycle with exceptional precision. While a true lunation lasts 29 days, 12 hours, 44 minutes and 2.8 seconds, Arnold & Son have achieved such precision that it would take 122 years for the display to drift by a single day from the actual lunar cycle, provided the watch is kept fully wound.

As for all Arnold & Son movements, the A&S1512 calibre is developed, manufactured, decorated, assembled, adjusted and cased up at the Chaux-de-Fonds manufacture. Equipped with two barrels and beating at 3 Hz, it gives the Perpetual Moon 41.5 Red Gold “Year of the Horse” a generous power reserve of 90 hours.

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