The Cartier Juste un Clou bracelet is one of the most counterfeited luxury accessories on the secondary market. Fakes have become so convincing that even experienced buyers need a reliable method to confirm authenticity. This checklist focuses on the specific details that change with each production year and are hardest for counterfeiters to replicate in 2026.

Key Authenticity Details

Start with the overall silhouette. The genuine Juste un Clou has a continuous, fluid curve with a precise nail head and tip. Fakes often have a slightly flattened curve or a tip that looks blunt. Check the gap between the nail head and the bracelet body — on real pieces it is uniform and just wide enough for the nail head to slide through without catching. Any asymmetry is a red flag.

The Screw Head Pattern

The screw head on the nail tip is a critical tell. Authentic Cartier uses a hexagonal screw with extremely crisp edges and a matte finish. The screw slot should be perfectly centered. After 2020, Cartier introduced a slightly deeper slot and a micro-etched logo on the underside of the nail head, visible under a loupe. Most fakes either skip this logo or etch it blurrily. Browse our value check guide for a detailed comparison of screw heads across different years.

Serial Numbers and Hallmarks

Every genuine Juste un Clou bracelet carries a four-digit serial number (e.g., CR5208) on the back of the clasp. The number is laser-engraved in a sans-serif font with a specific kerning. Counterfeiters often use a serif font or inconsistent spacing. Next to the serial, you will find the Cartier hallmark, the metal purity stamp (750 for 18K gold, 950 for platinum), and a small oval cartouche. The cartouche on fakes is often too large or shallow. Read our guide on resale photos and condition to see what hallmarks should look like under magnification.

Weight and Feel

The Juste un Clou is known for its substantial weight. A genuine 18K gold bracelet in size 17 weighs approximately 32–36 grams. Fakes made of gold-plated brass or steel feel noticeably lighter — often under 20 grams. The clasp mechanism on authentic pieces clicks smoothly with no resistance; counterfeit clasps can be stiff or gritty. Do not rely on weight alone, but combine it with a scratch test on an inconspicuous area (real gold does not leave a green streak on a ceramic plate). For a full weight and dimensions chart, see our buying guide.

Packaging and Documentation

Original packaging is a red flag itself. Cartier sends the Juste un Clou in a burgundy leather box with a cream interior and a magnetic closure. The box has a white Cartier logo embossed on the lid. Fakes often use a cardboard box with a printed logo. The authenticity card included should have a holographic sticker matching the bracelet’s serial number. Cards from fakes are glossy rather than matte. If the seller cannot provide the original box and card, demand additional proof. Check which designer bags hold value — the same principle applies to jewelry: complete sets command higher resale.

WhatsApp Value Check: What to Send

- Clear photo of the full bracelet on a white background (both sides).
- Close-up of the screw head showing the slot and any micro-etching.
- Macro shot of the serial number and hallmarks on the clasp.
- Photo of the box interior and the authenticity card hologram.
- Weight reading from a digital gram scale (place bracelet alone).