Short answer

A fake Calibre de Cartier is a copy of a watch Cartier built from 2010 to about 2018. Genuine models run the in-house 1904-PS MC automatic. Replicas run Chinese movements, a Miyota 9015, or an ETA 2824 clone. Any Calibre de Cartier with a quartz movement is fake. Case thickness, dial print, and case back engraving carry the tells. Steel copies sell for $80 to $500. Genuine steel 42 mm examples resell for $3,000 to $6,000.

Case and size

Cartier made the Calibre de Cartier in 38 mm and 42 mm. The Calibre Diver uses a 42 mm case with a fluted bezel. Replica cases run 0.5 mm to 2 mm thicker than the genuine part, and the crown guard sits at the wrong angle. The crown on the genuine watch holds a faceted blue cabochon. Fakes use glass or molded resin. Measure the candidate with calipers, then measure a known genuine case. Weigh both. Copies weigh less because the bracelet links are hollow.

Movement

The 1904-PS MC has 27 jewels, 28,800 vph, and a 48-hour power reserve. The rotor carries Cotes de Geneve stripes and the Cartier name. A watchmaker who opens the back sees the balance wheel placement in seconds. Replica movements use a different bridge layout under a decorated plate. A copy with a 40-hour reserve is running a 2824 clone or a Miyota. Cartier does not sell the 1904-PS MC to third parties.

Dial and hands

Genuine dials use applied Roman numerals with polished edges and a date window at 3 o'clock. The 42 mm has a small seconds subdial at 6 o'clock. Copies print the numerals flat, and the CARTIER lettering sits too wide or too narrow. Sword hands on the genuine piece are polished on all faces. Replica hands show brush marks and rough edges under a loupe. Lume plots on copies glow green or blue. Genuine Calibre lume reads pale.

Case back

Genuine case backs are engraved. The letters have depth and a polished floor. Copies use laser etching, which leaves shallow marks and a matte floor. Reference and serial numbers on the genuine watch sit in a straight line with even spacing. Fake stampings drift, and the font changes between digits. Photos of the case back at an angle show the difference.

Bracelet, strap, and clasp

Genuine steel bracelets have solid links, a polished center link, and brushed outer links. Copies rattle when shaken. The double-fold deployant clasp on leather straps carries a stamped Cartier logo with crisp edges. Fake stampings look soft. Strap stitching on copies uses a single row of even machine stitches. Genuine straps use a tighter, hand-finished stitch.

Price tiers

The replica market splits into three tiers. Low tier runs $80 to $150 with a 21-jewel Chinese movement, mineral glass, and a plated case. Mid tier runs $200 to $400 with a sapphire crystal, 316L steel, and an A2824. High tier runs $450 to $700 with a real ETA or Sellita movement and closer case geometry. No tier carries the 1904-PS MC.

Checks before you buy

Ask for a photo of the movement through an open case back. Ask for the case weight in grams. Ask for a side profile shot at lug level. Reject any listing with a quartz movement, a closed case back, or stock catalog photos. Have a watchmaker open the case after delivery and count the jewels.