Introducing The Arnold & Son Luna Magna Ultimate I Watch

The Luna Magna with its three-dimensional moonphase gets a formal suit of jewels.


Arnold & Son’s Luna Magna was recently presented at Watches and Wonders 2021 and showcased the brand’s first three-dimensional moon. A rotating sphere at 6 o’clock brought a new, sophisticated moonphase against the dial’s night sky and again demonstrated Arnold & Son’s incredible watchmaking prowess. The latest Luna Magna Ultimate I Limited Edition adds custom cut diamonds and blue sapphires to the case and dial, merging haute horology with luxury jewelry. This celestial masterpiece is limited to only eight watches and is art for the wrist.

The case is 18k white gold with a diameter of 44mm and height of 15.9mm. These rather bold dimensions allow for the wondrous scene on the dial, although the spectacle starts with the case. 112 baguette-cut diamonds are set around the bezel and lugs, totaling 5.90 carats. This continues on the hand-sewn blue or black alligator strap as the 18k white gold pin buckle is set with 26 diamonds totaling 0.97 carats. A domed sapphire crystal with anti-reflective coatings on both sides protects the dial, while the exhibition case back also integrates a sapphire window. Water-resistance is limited to 30 meters, but this piece is much more at home at a formal gathering than sitting poolside.

The main dial gets its astronomical aesthetic from blue-treated ruthenium crystals, while the large sub-dial with hours and minutes is white opal. The oversized, three-dimensional moon at 6 o’clock is 18k white gold, but its light/dark shades come from precious stones. An equal set of 161 diamonds and 161 sapphires complete the phases of the moon, totaling 1.6 carats of set jewels. The moonphase is so accurate that it would take 122 years for the movement to have an error of one day, although it’s easily adjustable via the crown.  

The back of the watch reveals the in-house Caliber A&S1021, a hand-wound movement that’s well finished with Côtes de Genève, perlage and blued, chamfered and polished screws. It has 35 jewels, beats at 3Hz (21,600vph) with a 90-hour power reserve. The back not only reveals the other half of the moon, but a precise moonphase indicator as well. A real presentation of Haute Horology in a unique, almost over-the-top piece.

The Arnold & Son Luna Magna I Ultimate Limited Edition retails for CHF 169,000 (excl. tax) and is again limited to 8 pieces. The watch finds a solid balance of form and function with its incredible, spherical moon and 8.47 carats of stones. And although expensive, it’s priced well for a handful of discriminating collectors.

Visit Arnold & Son here.