Short answer
A replica Must de Cartier Tank is a copy of the Cartier Must de Cartier Tank, a quartz watch Cartier sold from 1977 to the early 2000s. The original has a vermeil case: a sterling silver 925 core with gold plating. Most copies use gold-plated brass or stainless steel. Cartier does not make them, and the copies are not authorized.
The original: key facts
Cartier drew the Tank shape in 1917. The design takes its name from the Renault FT-17 tank. The Must de Cartier line started in 1977 as the entry level Cartier range, priced below the solid gold Tank models.
- Case: vermeil. Silver 925 core under 18k gold plating. French vermeil rules require at least 5 microns of gold over 925 silver.
- Size: the large model measures about 23 mm by 30 mm. Smaller models measure about 20 mm by 28 mm. Sizes changed across the production run.
- Movement: quartz.
- Crystal: mineral glass on most vermeil pieces.
- Dial: white or cream, black Roman numerals, blue sword hands.
- Crown: blue spinel cabochon set in a gold-plated crown.
- Strap: leather with a gold-plated ardillon buckle.
- Caseback: serial number, "Must de Cartier" text, silver hallmarks.
How copies differ
- Metal: brass or steel, not 925 silver. A brass case weighs less than a silver case of the same size.
- Hallmarks: French silver stamps are missing or shallow. The Minerva head mark and the maker's mark are the two to check.
- Gold plating: thin. Plating wears at the lugs, the caseback edge, and the crown.
- Movement: unbranded quartz. Cartier service parts do not fit.
- Dial: font weight and numeral spacing differ from the original print.
- Crystal: acrylic or mineral, with a different edge cut.
- Crown: the spinel cabochon is glass or plastic. The color shifts to purple or gray.
Authentication checks
- Density. Silver measures 10.49 g/cm3. Brass measures 8.5 g/cm3. Steel measures 7.9 g/cm3. A copy of the same case size is lighter.
- Hallmarks. Look at the caseback and the inner caseback for the Minerva head and a maker's mark.
- Magnet. Silver and brass do not pull a magnet. A steel case does. Use a weak fridge magnet.
- Crown stone. A spinel holds one color under light. Glass and plastic look flat.
- Movement. Original quartz movements carry a caliber number and a brand mark.
Legal status in the US
Cartier is a trademark of Richemont. Selling or importing counterfeit watches breaks federal law. 18 U.S.C. 2320 sets up to 10 years in prison and a $2 million fine for a first offense by an individual. The Lanham Act lets the trademark owner sue for damages. U.S. Customs and Border Protection can seize shipments. Buying a counterfeit for personal use is not a federal crime in most cases. Reselling one is.
Price context
Used vermeil Must de Cartier Tank watches trade in the low four figures in US dollars, depending on size, dial, and box and papers. Copies sell for a small fraction of that. The gap reflects the case metal, the movement, and the brand name.