The Cartier Santos Ref. 819901 moon phase in 18k yellow gold is a poetic take on one of Cartier’s most iconic designs. Featuring a beautifully proportioned 29mm case, the watch retains the signature exposed screws and Roman numeral dial, but adds a refined twist: a moon phase complication nestled at 6 o’clock. This romantic feature balances the dial’s classical layout and introduces a layer of visual depth and sophistication. Powered by a quartz movement, the 819901 offers precise, low-maintenance timekeeping wrapped in unmistakable Cartier style. The solid yellow gold case and bracelet enhance its presence on the wrist, offering warmth, weight, and understated luxury. A sapphire cabochon crown provides the final Cartier flourish.

This very example is in very good unpolished condition with lovely red patina around the bezel and bracelet, indicating the watch has never been polished and has not even been worn often. The moon phase disk did evolve the typical golden patina which I feel suits the “or massif” case quite well but can of course be changed upon request, besides the silvergrain dial is immaculate and features no patina. It’s accompanied by the original or massif quartz box!

---

---