The Handsome Montblanc 1858 Geosphere Annual Calendar with Minerva Movement

Montblanc‘s appreciation for Minerva‘s heritage drives its evolution as a watchmaker. The brand embraces Minerva’s time-honoured craftsmanship and savoir-faire by celebrating traditional techniques while exploring the possibilities of modern horology. This commitment is again evident in the newly unveiled 1858 Geosphere Annual Calendar, a timepiece poised to become a standout addition to Montblanc’s collection with its great calendar function and lovely view through the caseback.

The new Montblanc 1858 Geosphere Annual Calendar is available in a 42mm x 13.3mm case in either Lime Gold or stainless steel. It features Minerva’s signature fixed fluted bezel, a design element inspired by the company’s historic timepieces and the first fluted bezels dating back to the 1920s. A scratch-resistant, domed sapphire crystal with anti-reflective coating sits atop the satin-finished and polished case. At the same time, the matching caseback features a sapphire crystal window, offering a view of the movement. The fluted crown, adorned with Montblanc’s logo in relief, is positioned at 3 o’clock, and above it, you’ll find a recessed pusher for date adjustment.

The silvery-white dial is elegant and legible, featuring a two-frame aperture at 12 o’clock for the big date display. The month is indicated by rotating a ring at the dial’s periphery, with a special detail: July is replaced by “Minerva,” commemorating the registration of the Minerva trademark in July 1887, and a red arrow marks the current month.

A hand-painted, three-dimensional rotating globe crafted by a Swiss artisan is made from sapphire crystal and represents the Northern Hemisphere (with an option for the Southern Hemisphere upon request). It is marked by an orange Greenwich meridian line and encircled by a 24-hour scale with a Day & Night indication.

Closer to the centre, the dial features a minutes/seconds track and a textured chapter ring, where arrow-shaped faceted hour indices point inward the sunray-brushed circle. The stainless steel version has blue-coated indices and hands, while the Lime Gold edition features rose gold-coated details. Both variations offer white luminescent coating on hands.

The new Montblanc 1858 Geosphere Annual Calendar is powered by the hand-finished, manually wound MB M14.58 movement featuring a large 10mm balance wheel with screws. This calibre is based on the MB 14.08, previously used in the limited-edition Montblanc Heritage Pythagore series. The MB 14.08 itself draws inspiration from the historic Minerva “Pythagore” calibre 48, designed by André Frey in 1943. Unlike traditional vintage movements with curved bridges, calibre 48 embraced a linear design based on the golden ratio, a mathematical principle attributed to Pythagoras, believed to represent perfect harmony.

While the MB 14.58 builds upon the 14.08 base, it deviates from its straight lines and geometric angles and incorporates an additional bridge for the central seconds display. However, it retains the exquisite craftsmanship of its predecessor, featuring hand-chamfered edges on the rhodium-plated German silver plates and bridges, elegant Côtes de Genève decoration, and a gold-plated going train. The MB 14.58 movement, equipped with an annual calendar and world timer module, operates at 18,000 vibrations per hour and boasts a 65-hour power reserve.

Both versions of the watch are worn on a blue calf leather strap with an alligator print, secured with a triple-folding clasp featuring a fine adjustment system. The Montblanc 1858 Geosphere Annual Calendar in Lime Gold is limited to 30 pieces, while the stainless steel edition is limited to 100 pieces. Pricing is USD 45,500 in steel and USD 59,000 in gold. For more details, visit Montblanc.com.