Quick answer

Two tone means 316L stainless steel and 18k yellow or rose gold in the genuine Ballon Bleu de Cartier. Replicas copy the mix with plated gold. Common plate thickness is 3 to 5 microns. The genuine watch launched in 2007. Case sizes run 28mm to 42mm. Replica versions appear in 33mm, 36mm, and 40mm.

Case and finish

Genuine two tone Ballon Bleu uses solid 18k gold for the bezel, crown guard, and center bracelet links. Replica makers use 316L steel and gold plating. Plating wears at the clasp and crown guard. Look at the edge where gold meets steel. A sharp line points to plating. A soft line points to solid gold. Weight differs. A steel-and-gold 36mm Ballon Bleu sits near 110 grams. A plated replica often sits near 90 grams.

Dial and crown

The dial has a guilloché texture with Roman numerals. The crown sits under a blue sapphire cabochon. The cabochon is a key check. Genuine stones are clear and deep blue. Replica stones often look flat or purple. The fluted crown guard is another check. Genuine guards have 12 flutes. Replica guards often have 10 or 11 flutes. The date window sits at 3 o'clock on most sizes. Font weight matters. Replicas use thin or wide numerals.

Movement

Genuine two tone Ballon Bleu uses Cartier calibers. The 33mm runs the 076 or 057. The 36mm runs the 049. The 40mm runs the 1847 MC. Replica makers use Miyota 9015, Seiko NH05, or Chinese 2824 clones. Sweep rate is 28,800 vph on the 9015 and 2824 clones. The NH05 runs at 21,600 vph. Open the caseback to check. A genuine rotor has Cartier engraving and Côtes de Genève stripes.

Points to check

  • Crown cabochon color and shape
  • Flute count on the crown guard
  • Gold plating wear at the clasp
  • Weight in grams
  • Movement beat rate
  • Dial guilloché pattern alignment

Sizing

Two tone Ballon Bleu replicas come in 28mm, 33mm, 36mm, 40mm, and 42mm. Wrist size drives the pick. A 6.5 inch wrist fits 33mm and 36mm. A 7.5 inch wrist fits 40mm and 42mm. Bracelet links taper. Replica links often have a looser fit. Check the clasp for the Cartier double folding buckle. Genuine clasps have a crisp release.