Arnold & Son Perpetual Moon 41.5 Red Gold & Platinum Models

Arnold & Son’s Perpetual Moon watch is now available in two new interpretations in 41.5mm diameter case, in red gold or platinum. Its dial features a unique motif, Stellar Rays.

Perpetual Moon 41.5 Red Gold joins the permanent collection, while the platinum version is produced in a limited edition of 28 timepieces.

Arnold & Son Perpetual Moon 41.5 Red Gold

The Perpetual Moon 41.5’s cases in 18-carat (5N) red gold or 950 platinum have been redesigned. The lugs have been simplified so that instead of their original cross shape, they now present a tauter form of plunging bars with bevelled ends.

Arnold & Son Perpetual Moon 41.5 Platinum

The case, previously measuring 42 mm, is reduced to 41.5 mm without affecting the size of the dial. This has reduced the width of the bezel, drawing attention to the dial, its finishes, and its vast moon.

Arnold & Son Perpetual Moon 41.5 Platinum


The dials on these new creations present a unique finish known as Stellar Rays, its aesthetic obtained through skilfully irregular engraving. Several depths and widths of rays coexist and follow on from one another, creating their own rhythm, each generating a fluctuating interplay of light and a depth obtained by applying several layers of transparent lacquer.

Arnold & Son Perpetual Moon 41.5 Red Gold

This unique effect is employed in two forms. Perpetual Moon 41.5 Red Gold is combined with a dense, deep blue adorned with gold edging on the moon aperture, together with golden hands and hour markers. Perpetual Moon 41.5 Platinum is coupled with a salmon pink whose soft metallic radiance complements the rhodium-plated details on the dial.

Arnold & Son Perpetual Moon 41.5 Red Gold

Realistically depicted with hand-painted shadows, the large moon is enhanced with a luminescent material that is particularly intense in darkness yet invisible in daylight, giving way to the white mother-of-pearl disc. It is set against a blue PVD-treated grained sky and is surrounded by the constellations of the Big Dipper and Cassiopeia, also hand-painted and coated with Super-LumiNova.

Arnold & Son Perpetual Moon 41.5 Red Gold

The constellations have been chosen as a direct reference to John Arnold’s history as a maker of naval chronometers.

The Big Dipper and Cassiopeia have been used by navigators in the northern hemisphere since time immemorial to find their bearings and locate the North Star (Polaris). The position of the latter defines the North and its angular altitude, or position in the North-South plane, and allows the distance to the equator, i.e., latitude, to be estimated.

Arnold & Son Perpetual Moon 41.5 Platinum

On the case back, a secondary indicator allows the moon phase to be adjusted quickly and precisely. The hand-wound calibre that powers it, reference A&S1512, can track the development of its segments with exceptional precision.

Arnold & Son Perpetual Moon 41.5 Red Gold

The duration of a complete lunar cycle is 29 days, 12 hours, 44 minutes and 2.8 seconds. Arnold & Son has succeeded in representing it in such a way that it would take 122 years for this movement, if regularly wound, to accumulate a day’s difference between its display and celestial reality.

Arnold & Son Perpetual Moon 41.5 Platinum

Like all Arnold & Son movements, the A&S1512 calibre has been entirely developed, manufactured, decorated, assembled, adjusted and cased at the Manufacture in La Chaux-de-Fonds. The calibre features two barrels and an oscillation frequency of 3 Hz, providing a power reserve of 90 hours.

Technical details

Model: Arnold & Son Perpetual Moon 41.5

Red gold: 1GLBR.U01A.C200A
Platinum: 1GLBX.P01A.C200W

Hours, minutes, astronomical moon phases, second moon-phase indicator on the back

Calibre A&S1512, mechanical with manual winding
Jewels: 27
Diameter: 34 mm
Thickness: 5.35 mm
Power reserve: 90 hours
Frequency: 3 Hz / 21,600 vph
Main plate: rhodium-plated, Côtes de Genève stripes radiating from the centre
Bridges: polished and chamfered
Wheels: circular satin-finished
Screws: blued and chamfered, polished heads
Second moon-phase indicator: rhodium-plated and circular-grained

‘Stellar Rays’ decor, with blue or salmon-pink PVD treatment

Moon phases
Sky: grained, with blue PVD treatment
Constellations: hand-painted, with added Super-LumiNova
Moon: mother-of-pearl disc coated with Super-LumiNova, hand-painted details

Material: 18-carat (5N) red gold or 950 platinum
Diameter: 41.5 mm
Thickness: 11.30 mm
Crystal: Domed sapphire, with an anti-reflective coating on both sides
Case back: Sapphire crystal, with an anti-reflecting coating
Water-resistance: 30 m / 100 ft

Blue alligator leather, hand-stitched
Buckle: Pin buckle, 18-carat (5N) red gold or 18-carat white gold

Red gold: non-limited
Platinum: 28 timepieces

Swiss retail prices
Red gold: CHF 34,500 including taxes (subject to change)
Platinum: CHF 46,500 including taxes (subject to change)