The Tortue with diamonds. White gold, hand-wound, papers.

Cartier is the house that made the wristwatch a shape rather than a circle: the Tank of 1917, the Tortue of 1912, the Tonneau of 1906, each a case with Roman numerals, blued sword hands and a cabochon in the crown. Cartier makes them in gold and in steel, in quartz and in mechanical, and on the pre-owned market the gold ones sit where a Rolex Datejust does in price and a step above it in how they read across a table.

The Tortue is the tonneau Cartier drew in 1912, the case that curves like a tortoise shell, and in the 1998 to 2008 Collection Privee Cartier Paris years it came in gold with hand-wound movements and, in the top versions, diamonds set into the case. This one fits that description: white gold, hand-wound, diamonds on the front and flanks, a guilloche dial. myGemma does not give the reference or the calibre, so ask for the caseback numbers; a Collection Privee piece carries them, and the service papers should match.

myGemma gives the metal as 18k white gold, the shape as tonneau, the movement as mechanical hand-wound, the band as black alligator with a deployment clasp, the wrist size as 7 inches, the condition as Excellent with minimal signs of wear, and service papers and its own certificate as included. It gives no Cartier reference, calibre, case size or water resistance, and the copy states none. The diamonds, guilloche dial and cabochon crown are from the photograph.

myGemma authenticates in-house and is not a Cartier authorised dealer, and Amazon adds its 30-day return window. Ask for the reference and the caseback numbers, the service papers, and when it was last serviced. Nothing here was measured on the watch.

This unit is sold by myGemma, a reseller that authenticates in-house and issues its own certificate of authenticity through Amazon Luxury Stores, authenticated by the seller with Amazon’s 30-day return window on top; it is one piece, and when it sells the listing goes away, so the second button opens the live search for Tortues.

Gold Cartiers have resold close to what pre-owned buyers paid, sometimes more, sometimes less; that is a pattern, not a promise, and nothing here is investment advice.