Montblanc Star Twin Moonphase


One moon – two hemispheres
The Montblanc Star Collection blends the classical elegance of fine Swiss watchmaking with the characteristic formal language of Montblanc. The round cases, black Arabic numerals and sumptuous finishes in the tradition of Haute Horlogerie, such as guilloché dials, endow these watches with a timeless beauty. All of these characteristics are expressed in the new Montblanc Star Twin Moonphase.

Its automatic Montblanc calibre MB 29.13 was constructed for a new type of complication that is used exclusively by Montblanc and gives the watch its name: a moon-phase display that shows the moon’s phases in both the Northern and Southern hemispheres and the age of the moon in days.

The earth natural satellite
A moon-phase display, which has traditionally numbered among the most popular horological complications, always adds a very poetic aspect to a wristwatch. For countless millennia, people in every culture have felt emotionally connected to the night’s brightest celestial body.

Most people, however, are unaware that the moon’s phases appear differently depending upon whether they’re observed from the Northern or the Southern Hemisphere. The lunar phases follow one another in the same sequence regardless of an observer’s location: full moon is full moon and waxing moon is waxing moon, but the geometries of the waxing and waning moon as seen from the Southern Hemisphere are mirror images of their counterparts as viewed from the North. The waxing moon’s crescent always appears to curve toward the right when seen by an observer in the Northern Hemisphere, but curves toward the left when viewed from the South. An analogous situation prevails for the waning moon’s crescent, which curves toward the left for observers in the Northern Hemisphere and toward the right for viewers below the Equator. Most timepieces with moon-phase displays depict the lunar phases as they appear to observers in the North because clocks, watches and the moon-phase display were invented in the Northern Hemisphere and because the majority of people live north of the Equator.

The Moon from the North and the South
The situation is different on the face of the Montblanc Star Twin Moonphase, which also does justice to the perspective of people who dwell in the Southern Hemisphere. A classical moon-phase display with its characteristically shaped window (to emulate the geometry of the waxing or waning moon as it appears to viewers in the Northern Hemisphere) is combined here with a pointer for the moon’s age in days. This slim hand is positioned diametrically opposite the conventional moon-phase display in the lower half of the lunar subdial, where it points to symbols that show the appearance which the moon’s phases present to viewers in the Southern Hemisphere.

All this takes place at “6 o’clock” on a classical beautiful subdial which has been thoughtfully conceived down to its very last detail. The moon’s age is shown in days along the periphery of the subdial, the upper portion is reserved for a familiar moon-phase display with a characteristically shaped window in which golden-coloured Luna glides above a dark blue background and gradually changes her appearance to keep pace with the phases of the moon as seen by observers in the Northern Hemisphere. The surface below it is tastefully adorned with a pattern shaped like Montblanc’s emblem and wreathed by moon-phase symbols as they appear in the sky above the Southern Hemisphere.

A High-Class Dial 
The dial is adorned with a fine guilloche décor – a classical element in the design vocabulary of haute horlogerie that is used on the dials of the Montblanc Star watches and concentrically develops the contours of the Montblanc emblem on the moon-phase subdial of the Twin Moonphase. This continues to the clearly structured scale for the minutes and seconds along the outermost periphery of the dial. The scale has an aperture between “one o’clock” and “two o’clock” for the asymmetrically arranged pointer date, as well as a  cartouche at “10 o’clock” with the MONTBLANC script logo and the word “automatic”, which alludes to the self-winding mechanical movement. The unconventional arrangement of the date display, the red accents in the minute and calendar scales, and the crescent-shaped tip of the date pointer give this wristwatch a very distinctive look. Black Arabic numerals, which are a typical feature of the Montblanc Star Collection, clearly contrast with the silvery grey background. This setting strongly contrasts with blued steel hands to assure excellent legibility: leaf-shaped hour- and minute-hand, a baton-shaped second-hand with the revised Montblanc emblem as a counterweight, a slim and straight pointer for the moon’s phases and age, and a very slender date-hand with a bright red crescent at its tip.

Cases with the Sheen of Stainless Steel  
This classical face is placed in a special polished stainless steel case, which has contemporary proportions with a diameter of 42 mm and an overall height of 12.7 mm. A domed and antireflective sapphire crystal protects the dial. A pane of sapphire crystal is inserted into the screwed back to provide a clear view of high- quality mechanical Calibre MB 29.13. This self-winding movement is equipped with a special complication, solely used by Montblanc in this configuration, to indicate the twin moon phase. The movement with asymmetrical pointer date has all the fine attributes of the art of Swiss watchmaking. It ticks at a pace of 28,800 semi-oscillations per hour (4 Hz) and, if the watch is left unworn for a longer interval, the calibre can be manually wound by turning the fluted, readily graspable, stainless steel crown with inset Montblanc emblem. The date and moon-phase displays can be adjusted in single-day increments via two buttons inset into the flank of the case. This timepiece is worn in the classical manner on a strap, which is crafted from alligator leather with large reptilian scales. The wristband is secured by an exclusive triply folding stainless steel clasp which enables the owner to quickly and easily slip the watch on and off. The Montblanc Star Twin Moonphase will be available in Montblanc boutiques and at selected watch and jewellery stores starting in the autumn of 2014.

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Montblanc Star Twin Moonphase
Ref.: 110642

Movement Calibre MB 29.13

Movement type Mechanical movement with automatic winding; hours, minutes and seconds from the dial’s centre; moon’s phase; pointer date

Number of rubies 27

Power reserve Ca. 42 hours

Balance Smooth hoop

Frequency 28,800 A/h (4 Hz)

Hairspring Flat

Displays Hours, minutes and seconds from the dial’s centre; moon’s phases depicted as they appear in the Northern and Southern Hemispheres; pointer date at “2 o’clock”


  • Case Stainless steel case with a scratch-resistant domed sapphire crystal that is antireflective; back with transparent pane of sapphire crystal
  • Dimensions Diameter = 42 mm, height = 12.17 mm
  • Watertightness To 3 bar (30 m)
  • Dial Silver-coloured dial with finely embossed Montblanc emblem; blued hands; black Arabic numerals
  • Crown Fluted stainless steel crown with Montblanc emblem
  • Wristband  Black alligator-leather strap with large scales and triply folding stainless steel clasp