Short answer
A replica Rotonde de Cartier in rose gold with diamonds is a counterfeit. The genuine watch has an 18k pink gold case and natural diamonds. Replicas use gold-plated steel and cubic zirconia. US law bans trafficking in these watches. Customs officers seize shipments and destroy the goods.
What the genuine Rotonde de Cartier is
Cartier sells the Rotonde de Cartier as its round-case line. Pink gold references measure 40 mm to 42 mm across. The 1904-PS MC automatic caliber has 27 jewels, runs at 28,800 vibrations per hour, and holds a 48-hour power reserve. A sapphire crystal covers the dial. The strap is alligator leather with an 18k gold folding clasp.
Diamond references
Cartier sets diamonds on the bezel, the lugs, or the dial, depending on the reference. Stone counts and carat weights change with each reference number. Cartier publishes those numbers on the product page for each watch. I do not have a verified count for every Rotonde reference.
What the replica market uses
- Case: 316L stainless steel with rose gold PVD plating, 3 to 5 microns thick.
- Stones: cubic zirconia, glass, or lab-grown diamonds sold as natural.
- Movement: a Chinese automatic, often a copy of the ETA 2824 design.
- Weight: a plated steel case weighs about half of a solid 18k gold case of the same volume.
- Water resistance: sellers claim 30 m to 50 m. Gaskets are not tested at the factory.
How to test the metal and the stones
Look inside the caseback for the 750 hallmark and the Cartier maker's mark. An XRF scan or an acid test at a jeweler measures gold content. A steel case attracts a magnet. Solid gold does not. A jeweler with a gem tester or a refractometer separates diamond from cubic zirconia in seconds. Diamond conducts heat. Cubic zirconia does not.
Legal status in the United States
18 U.S.C. § 2320 makes trafficking in counterfeit goods a federal crime. A first offense carries up to 10 years in prison and a fine. A second offense carries up to 20 years. Trademark owners can sue under the Lanham Act. CBP seizes counterfeit watches at ports of entry and destroys them. A personal-use purchase is not a federal crime in most cases, but the watch can be seized with no refund.
Price
Solid pink gold Rotonde references with diamond bezels sell in the tens of thousands of dollars at Cartier boutiques. Replica listings run from about $300 to $800. Price alone does not prove authenticity.
Stone disclosure rules
The FTC Jewelry Guides require sellers to name simulated stones as simulations. A seller who calls cubic zirconia a diamond breaks the rule. Lab-grown diamonds must be labeled as lab-grown.