Cartier Tank Louis WGTA0011: specifications and what to check

Mineral crystal, on a solid gold watch

Cartier specifies the crystal on this reference as mineral.

Not sapphire. That is a genuine and slightly counter-intuitive specification — this is a solid rose gold 750/1000 case with a glass that scratches in ordinary wear.

It changes both how you grade the watch and what you may claim.

Grading. A scuffed mineral crystal is a wear surface behaving as designed, and it can frequently be polished. That is much cheaper than the sapphire replacement a chipped crystal implies elsewhere, so do not discount it as though it were.

Claiming. Writing "sapphire crystal" because the watch is gold and expensive is a specification the manufacturer does not state. Buyers at this level check.

Cartier does fit sapphire to other references documented here — the Santos, the Tank Française — so this is a deliberate difference rather than an omission.

The page argues with itself about the size

Worth handling carefully, because a dealer can look like they are spinning it either way.

Cartier's specification bullet for this reference says Medium model. The page's own <title> and its og:title both read "Tank Louis Watch - Rose Gold, Large Model".

Those cannot both be right, and it is not a dealer's job to resolve a manufacturer's internal contradiction.

The honest handling is to quote the specification — medium — give the case dimensions, which are not in dispute at 33.7 mm x 25.5 mm, and state that Cartier's page title says otherwise. A buyer who later finds the title will see you had already flagged it rather than chosen the flattering reading.

Lead with the dimensions in any case. They describe the watch; the model name does not.

Hand-wound, with no reserve figure

The movement is the calibre 1917 MC, a manufacture mechanical movement with manual winding.

Cartier publishes no power reserve. Do not supply one.

The usual hand-winding discipline applies, and it matters more here than on a steel watch. Wind from stopped, feel the tension build evenly, and stop at the stop — there is no rotor and no slipping bridle. Tell the buyer the same at handover, because a Tank Louis is exactly the watch someone buys as their first mechanical piece.

Polished gold, nowhere to hide

The case is rose gold 750/1000, and the Tank Louis is polished across its whole exterior.

That is the least forgiving combination there is for condition. Gold is soft and marks easily; a fully polished surface shows every one of those marks; and refinishing gold removes material that does not come back.

Take it to a window, angle it until a hard line reflects along the case side, and follow the reflection all the way round. You are reading accumulated haze as much as individual scratches.

The crown carries a sapphire cabochon — a set stone in a part handled every time the watch is wound, which on a hand-wound watch is daily. Check it for chips and confirm it is seated.

The strap is semi-matte brown alligator with an ardillon buckle in rose gold. Price those separately: the strap is a consumable, the buckle is precious metal, and a buyer at this level expects a presentable strap.

Water resistance is 3 bar (30 meters) — rain and hand washing, on a leather strap. Say it in words.