Haute Watch of the Week: Cartier Rotonde Earth and Moon Tourbillon

This beautiful timepiece gets points for best use of lapis lazuli in a timepiece and extra double points for presenting the moon phase indication in a way that departs from the traditional gold sun on a blue disc that moves under a window on the dial.

The display on this dial is utterly unique, with the phase of the moon shown on demand when the user presses the push-piece at two o’clock. The lapis lazuli stone disk emerges from its hiding place under the Roman numeral IIII to cover the tourbillon aperture in a way that represents the phase of the moon. By pressing the push-piece again, the stone disk returns to its original position. The other push-piece is used to set the second time zone, indicated by the 24-hour rotating disk at 12 o’clock.

The 47mm case is platinum, a good sign that this is a limited edition – 50 pieces only. The openworked grid with Roman numerals, which sits over the lapis dial, is also platinum. The watch contains the beautifully openworked, rhodium-plated caliber 9440 MC, the result of a collaboration between Cartier R&D and Renaud & Papi. It is visible through the sapphire caseback, and has a three-day power reserve.

Photos courtesy Cartier.