Short answer
A fake Rotonde rose gold diamond is a copy of the Cartier Rotonde de Cartier with a diamond-set bezel. Most copies use 316L stainless steel with rose gold plating, not 18k gold. Bezel stones are cubic zirconia, moissanite, or lab-grown diamonds, not natural Cartier stones. Street price runs from $150 to $600. A genuine Rotonde de Cartier in rose gold with a diamond bezel sells at $25,000 and up at retail.
Case and finish
The genuine Rotonde de Cartier case is 18k rose gold or 18k white gold. 18k rose gold is 75% gold, 20% copper, 5% silver. Copies machine the same outline in 316L steel, then plate it.
- Plating thickness: 3 to 10 microns of rose gold color over a nickel or copper strike layer. Gold content is zero at that thickness.
- Color match: copper-heavy plating reads pinker and darker than 18k rose gold under daylight.
- Weight: a 42 mm steel copy lands at 90 to 120 g. The 18k gold original lands at 150 to 190 g on the same bracelet.
- Crown: Cartier uses a blue or pink sapphire cabochon. Copies use glass, spinel, or dyed quartz.
Bezel stones
Cartier sets brilliant-cut diamonds on selected Rotonde references. Copy bezels use three stone types.
- Cubic zirconia. Hardness 8.25 Mohs. Facets cloud and scratch after 12 to 24 months of daily wear.
- Moissanite. Hardness 9.25 Mohs. Refractive index of 2.65 against 2.42 for diamond, so it throws more color flash.
- Lab-grown diamond. Same hardness and refractive index as natural diamond. Rare in the copy market below $700.
Setting style matters more than stone type for the look. Copy prongs sit higher and snag cloth. Grain setting on the original sits near flush with the bezel surface.
Movement
Genuine Rotonde models run in-house Cartier calibers, including the 1847 MC, 1904-CH MC, and 430 MC families. Copies use three grades.
- Chinese 2813 automatic. 21,600 vph. Budget tier at $150 to $250.
- Seagull ST2130 or Hangzhou 6300. 28,800 vph. Built to the ETA 2824 layout.
- ETA 2824 or Sellita SW200. Top tier at $450 and above.
Check beat rate with a timegrapher app on a phone. 28,800 vph points to grade two or three. 21,600 vph points to grade one.
Legal note
US Customs seizes counterfeit watches under 19 CFR 133. Cartier holds trademarks on the Rotonde case shape, the crown cabochon, and the dial layout. Sale of a copy is a civil offense in the US. A single item for personal use can still be seized and destroyed at the border.
Checks before you buy
- Ask for a caliper photo showing case diameter and thickness in mm.
- Ask for stone type and total carat weight in writing.
- Ask for a movement photo with the caseback removed.
- Ask for a timegrapher printout with rate and amplitude.
- Ask for plating thickness in microns.
- Confirm the return window and condition terms in writing.