Arnold & Son Luna Magna Ultimate I

Arnold & Son Luna Magna Ultimate I – Celestial brilliance

Reading Time: 3 minutes

A watch face featuring ruthenium crystals and a dial made of white opal. A bezel set with baguette-cut diamonds. A three-dimensional moon paved with blue sapphires and diamonds. The first chapter of the Arnold & Son Luna Magna Ultimate series illustrates light, astronomical precision and the truly exceptional.

After presenting the Luna Magna, Arnold & Son set out to create a series of high-end jewellery interpretations of its three-dimensional moon model. In addition to the technical feat of placing a mechanical star measuring 12mm inside a watch, this piece displays superlative jewel-setting ability, both in the stones and techniques used. With paved and invisibly-set precious stones, Arnold & Son have applied their exceptional know-how to creating eight Luna Magna Ultimate I watches. Poetic and rare, they reveal an outstanding level of detail.

Arnold & Son Luna Magna Ultimate I

High altitude

Only the most precious materials are used in the Arnold & Son Luna Magna Ultimate I limited series. The case, measuring 44mm in diameter, is made of white gold and set with 7.62 carats of the highest quality diamonds. These include 20 baguette-cut diamonds on the case’s lugs, cut one by one to fit the unique shape of each mount.

White orbit

A fine ring resembling the ring around Saturn constitutes the bezel, orbiting the Arnold & Son Luna Magna Ultimate I case. It contains 112 baguette-cut diamonds totalling 5.90 carats. Light can enter freely, just as it would an open prism, thanks to the dual-row invisible setting which allows for radiance beyond compare.

Arnold & Son Luna Magna Ultimate I

Blanket of blue

The material used to make the watch face itself is just as exceptional, owing to its rarity. Hundreds of pure ruthenium crystals make up that sparkling blue façade. This extremely hard metal belongs to the platinum group, which means they are found together in the same ore. Separating them is a complex process that makes ruthenium ten times rarer. Here, it has been reshaped into crystals which are placed on the face plate before being blued.

Iridescent display

Within the circle of blue radiance lies a dial in the conventional sense, featuring twelve Roman numeral markings, the Arnold & Son signature and the hands. This off-centre subdial owes its delicate colour to white opal, and its finesse befits a piece of the finest jewellery such as the Luna Magna Ultimate I.

Double hemisphere

Beneath the timepiece, the three-dimensional moon is the standout feature of the Arnold & Son Luna Magna watches. Gem-setting of the utmost intricacy coats the entire white gold sphere. It is divided into 161 brilliant-cut diamonds for daytime and as many blue sapphires for night-time. The line between the two colours is a ripple of blue and white along the outline of the stones.

Arnold & Son Luna Magna Ultimate I


The Luna Magna Ultimate I is made with the Arnold & Son A&S1021 calibre, which is entirely developed, manufactured, assembled and adjusted in-house at Arnold & Son. This hand-wound calibre, designed around the lunar globe, has a power reserve of 90 hours and a regulating organ at a frequency of 3 Hz. As for the case back, the movement provides a second display for the lunar phase, featuring easy-to-read graduations for utmost precision when correcting the lunar globe.


The sophistication of this celestial mechanism also lies in its astronomical accuracy. The length of a full moon cycle is 29 days, 12 hours, 44 minutes and 2.8 seconds. Arnold & Son has produced a likeness such that it would take 122 years for the movement to accrue a one-day interval between the watch display and the true celestial cycle. Nevertheless, this error is easy to correct given that the lunar function on the Luna Magna Ultimate I is directly accessible from the crown. Arnold & Son’s complete mastery of the watchmaking process allows for this practical touch.

Arnold & Son Luna Magna Ultimate I

Arnold & Son Luna Magna Ultimate I Technical Specifications and Price

Product reference: 1LMMW.Z01A.C177A


  • hours, minutes, astronomical lunar phases (one-day correction every 122 years), moon phase indicator on case back


  • Calibre: A&S1021, hand-wound mechanism
  • Jewels: 35
  • Diameter: 37.60 mm
  • Height: 12.00 mm with three-dimensional moon (4.75 mm without the moon)
  • Power reserve: 90 hours
  • Frequency: 3 Hz / 21,600 vph
  • Finishes
    • main plate: circular-grained
    • bridges: chamfered, radiating Côtes de Genève
    • wheels: circular satin-brushed
    • screws: blued and chamfered, polished heads
    • moon phase indicator: circular satin-brushed

Watch face

  • dial: blue-treated ruthenium crystals
  • subdial: white opal


  • diameter: 12.00 mm
  • 18 carat white gold
  • set with 161 diamonds (~0.75 ct) and 161 sapphires (~0.85 ct)


  • Material: 18 carat white gold, bezel with dual-row invisible setting and studded lugs, with a total of 112 baguette-cut diamonds (~5.90 ct)
  • Diameter: 44.00 mm
  • Thickness: 15.90 mm (with crystal)
  • Crystal: domed sapphire with an anti-reflective coating on both sides
  • Back: sapphire crystal with an anti-reflective coating on both sides
  • Water-resistance: 30 metres / 100 feet


  • Material:
    • outside: blue or black alligator leather
    • inside: blue or black alligator leather
  • hand sewn
  • Buckle: pin, 18 carat white gold, set with 26 baguette-cut diamonds (~0.97 ct)


  • Diamonds
    • total weight: ~7.62 ct
    • colour: D-E-F
    • clarity: IF-VVS
  • Sapphires
    • total weight: ~0.85 ct
    • colour: blue
    • clarity: loupe clean

Limited edition: 8 pieces

Global retail price: CHF 169,000 excl. tax (subject to change) excluding tax

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.