Montblanc 1858 Geosphere Annual Calendar Debuts In Steel And Lime Gold
Montblanc expands its 1858 collection with the introduction of the 1858 Geosphere Annual Calendar, a watch that integrates complex functionality with high-end finishing and a strong connection to Minerva’s technical heritage. This new model brings together a rare combination of annual calendar and world time functions in a manually wound timepiece.
The watch is presented in a 42mm case, available in two materials: stainless steel and Lime Gold, the latter being a proprietary alloy exclusive to Montblanc. At 13.3mm thick, the case features a satin-brushed finish with polished accents and is topped by a domed sapphire crystal with anti-reflective coating. A fluted bezel, referencing Minerva’s historic designs from the 1920s, adds a distinctive vintage signature.
The crown, placed at 3 o’clock, is fluted and embossed with the Montblanc emblem. Just above it, a recessed corrector enables easy adjustment of the calendar.
On the silvery-white dial, legibility is prioritized through a balanced layout. A double window at 12 o’clock displays the big date, while a peripheral rotating month ring uses a red arrow as an indicator. A nod to the past is included with the inscription “Minerva” in place of “July,” referencing the brand’s registration in that month in 1887.
The lower half of the dial showcases a hand-painted 3D globe, crafted from sapphire crystal and illustrating the Northern Hemisphere, complete with a 24-hour scale and day/night indication. The Greenwich meridian is highlighted in orange. Upon request, the globe can be configured to represent the Southern Hemisphere.
Around the dial’s center lies a sunray-brushed chapter ring, bordered by a textured minute and seconds track, and marked with arrow-shaped indices. The stainless steel model features blue-coated markers and hands, while the Lime Gold version includes rose gold-coated elements. Both versions are treated with white Super-LumiNova® for enhanced visibility in low light.
Driving the timepiece is the Calibre MB M14.58 manual movement, which operates at 18,000 vibrations per hour (2.5 Hz) and delivers a 65-hour power reserve. This calibre builds upon the MB 14.08, previously used in the Montblanc Heritage Pythagore line, which itself draws lineage from the Minerva calibre 48 developed in 1943. While the MB 14.08 was known for its straight-line architecture based on the golden ratio, the new MB M14.58 adds complexity with an additional bridge to support a central seconds hand and integrates the annual calendar and world time modules. It’s adorned with rhodium-plated German silver bridges, hand-chamfered edges, Côtes de Genève striping, and a gold-plated gear train.
Each watch is fitted with a blue calfskin leather strap, embossed with an alligator motif, and equipped with a triple-folding clasp featuring a micro-adjustment system.
Production is strictly limited: 100 pieces in stainless steel and just 30 pieces in Lime Gold. The retail prices are USD 45,500 and USD 59,000, respectively.
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General Specifications:
Brand: Montblanc
Model: 1858 Geosphere Annual Calendar
Reference: 134026 (steel), 134027 (lime gold)
Dial: Silvery-white
Case Material: Stainless steel, Lime gold
Case Dimensions: 42 mm Diameter, 13.30 mm thickness
Crystal: Sapphire glass
Case Back: Sapphire glass
Strap: Blue calf leather strap with alligator pattern and triple-folding clasp
Calibre: MB 14.58
Functions: Hours, minutes, date, month, world time, day/night indicator
Winding: Hand-wound
Frequency: 2.5 Hz (18,000 Vph)
Power Reserve: 65 hours
Price: USD 45,500 (steel), USD 59,000 (lime gold)
Availability: Now
Limited Edition: Yes, 100 pieces (steel) and 30 pieces (lime gold)
