A phony Rotonde Earth Moon is a watch sold as the Cartier Rotonde de Cartier Earth and Moon that Cartier did not make. Cartier launched the model in 2014. The genuine watch pairs a tourbillon with a moon phase that a rotating Earth disc covers on demand. Copies come in two groups: low-grade counterfeits with printed dials, and higher-grade replicas with automatic movements. No copy matches the real movement, the stone dial, or the pusher function.
Cheapest Rotonde Earth Moon Watch: A Buying Guide
What the genuine watch does
Cartier built the Earth and Moon as a small-series piece in platinum. Case size sits near 47 mm. Thickness passes 16 mm. The dial carries a stone disc painted with the Earth over a moon aperture. A pusher on the case side turns that disc. One position leaves the moon open. The other parks the Earth over the aperture. The moon phase tracks the synodic month: 29 days, 12 hours, 44 minutes.
counterfeit rotonde earth moon
Cartier uses an in-house caliber. The caliber number is engraved on the caseback and differs by reference. The model is a dress watch. It has no dive rating.
Signs of a phony Rotonde Earth Moon
- Case metal and weight. Platinum has a density near 21 g/cm3. Steel sits near 7.8 g/cm3. A platinum case of the same size weighs about 2.5 times a steel case. Copies use steel or brass with plating, so they feel light in the hand.
- Dial material. Genuine discs use hard stone. Copies print the Earth on flat lacquer. Photos show hard edges on the continents.
- Pusher function. Press the pusher. On a copy the Earth disc does not move, or it moves by hand only.
- Moon phase cycle. A true moon phase advances once per 29.53 days. A day and night disc advances once per 24 hours. Watch the aperture for two days. A shape that shifts in one day is a day and night disc.
- Tourbillon. A real tourbillon cage holds the balance and escapement and turns once per minute. Copies show an open-heart cutout or a disc that spins with the rotor.
- Caseback. Check the caliber number, the reference, the metal stamp, and the serial. Copies reuse one serial across a batch.
- Price. Genuine examples trade in six figures. Copies sell from about $300 to $3,000.
Why the complication resists copying
A tourbillon cage holds 60 to 80 parts and needs hand adjustment. A moon phase needs a 59-tooth wheel and a reduction gear train. Stone dials need lapidary cutting. These three parts of the build set the price of the genuine watch.
The Cheater Rotonde Earth Moon: A Comprehensive Guide
Checklist before you pay
- Ask for a photo of the movement with the caseback removed.
- Ask for a video of the pusher in use.
- Ask for case diameter and thickness with calipers in the photo.
- Ask for the case weight on a scale.
- Ask for a two-day video of the moon aperture.
Legal note for US buyers
US Customs and Border Protection can seize goods that carry a counterfeit mark, under 19 U.S.C. 1526. Selling a watch as a Cartier when Cartier did not make it is trademark infringement. Shipments into the US that carry the Cartier mark on the dial or caseback carry seizure risk.