Short answer
The phrase "fake rendez-vous back of the moon" covers two different watches. Rendez-Vous is a Jaeger-LeCoultre collection, and rendez-vous is French for appointment. Back of the moon is collector shorthand for the Omega Speedmaster Dark Side of the Moon, a full black ceramic chronograph. Fakes of both exist, and they fail in different places. You confirm a genuine example by matching the reference number, the case engravings, the movement, and the factory paperwork. Photos of the box prove nothing.
What each watch is
The Jaeger-LeCoultre Rendez-Vous is a slim, dress-oriented line, often with a diamond-set bezel and an in-house automatic calibre. The Omega Dark Side of the Moon is a Speedmaster with a ceramic case, a zirconium-based dial, and a co-axial Master Chronometer movement. One is a quiet jewelry-adjacent dress watch. The other is a large sports chronograph. Treat them as two separate inspections.
Prerequisites
- A 10x loupe
- A phone camera that shoots macro
- Digital calipers and a gram scale
- The factory reference number and case diameter for the exact model
- The serial number in writing from the seller before you inspect
- Access to the brand's own service or boutique for a final check
Verify a Jaeger-LeCoultre Rendez-Vous
- Read the reference and serial numbers on the caseback under the loupe.
- Compare the engraving depth and font against a known genuine photo of the same reference.
- Measure the case diameter and thickness with calipers and compare to the catalog figure.
- Weigh the watch. Gold references should land close to the published weight for that metal.
- Check the gold hallmark inside the caseback on precious metal models.
- Inspect the dial printing, the applied numerals, and the polish on the bezel under magnification.
- Look at the movement through the display back and confirm the calibre number etched on the rotor.
- Test the crown action and the date change. A gritty or slow jump is a warning sign.
Verify an Omega Dark Side of the Moon
- Confirm the case is ceramic, not coated steel. Ceramic is warm and non-magnetic; steel with a coating chips at the edges.
- Look for the zirconium and ceramic markings on the caseback engraving.
- Check the movement designation on the rotor and confirm it is a Master Chronometer calibre.
- Request the Master Chronometer certificate number and verify it against Omega records.
- Examine the tachymeter scale and the sapphire crystal for the double anti-reflective coating.
- Press the chronograph pushers. Ceramic pushers should feel crisp with no lateral play.
- Weigh the watch on the gram scale. Ceramic on a bracelet sits in a narrow weight band.
Red flags common to both
- Seller refuses to give the serial number before payment
- Reference number does not match the dial layout or the case metal
- Blurred or cropped photos only
- Price far below the current secondary market range
- Warranty card with a different serial than the case
- A "Swiss made" print that is too large, misaligned, or missing entirely
Before you buy
Budget for an independent authentication on any four-figure purchase. A watchmaker with brand parts access can open the case, read the movement, and confirm the serial in under an hour. If the seller objects to that, walk away. On the Rendez-Vous, insist on the correct brand documentation. On the Dark Side of the Moon, insist on the Master Chronometer card. Replica sellers online often mix the two names to catch search traffic, so verify the model first, then the watch.