Putting a chronograph behind a stone dial is a considerably harder proposition than putting a time-only movement there, and this reference is the one place in the collection where it has been done. The difficulty is structural. A chronograph needs openings in the dial for its counters, and cutting three separate apertures into a slice of onyx means machining a brittle mineral in a pattern that leaves narrow bridges of material between the holes. Every one of those bridges is a place the dial can crack during manufacture, and the failure rate on a stone chronograph dial is accordingly higher than on a solid one. The case is white gold at 41 mm, and the dial carries baguette-cut diamond hour markers. Onyx is also the only stone the collection uses on more than one kind of watch. It appears here on a chronograph and again on a flying tourbillon in black ceramic, and the two references treat it in opposite ways. On the tourbillon the material is left entirely uninterrupted apart from the cage aperture. Here it is cut through three times over.
The case is white gold in the Code 11.59 construction, round when viewed from above and octagonal through the middle section, with hollowed lugs welded to the case band rather than machined as part of it. The dial is black onyx, a chalcedony chosen for uniformity rather than for pattern, and on a chronograph that uniformity does real work, since a figured stone would compete with the counters and make the display harder to read. Baguette-cut diamond hour markers stand above the black field. Baguettes rather than round stones is the correct decision on a dial of this kind, because a rectangular stone reads as a defined bar and keeps its position against a busy display where a brilliant would scatter light and blur into the counters. A black lacquered inner bezel closes the outer edge and white gold hands cross the whole arrangement. The strap is black rubber-coated with a white gold pin buckle. Setting a stone dial also constrains where the markers can go. Each baguette has to be seated into the onyx rather than fixed through it from behind, since drilling a brittle mineral for marker feet risks the whole dial, so the setting has to hold from the front face alone. That is a different technique from setting a metal dial and a considerably less forgiving one.
The function set is a flyback chronograph with hours, minutes, small seconds and a date. Flyback means the running chronograph can be zeroed and restarted with a single push rather than requiring a stop, a reset and a start in sequence, which is the behaviour that matters to anyone timing consecutive intervals rather than one event. Small seconds runs alongside so the watch remains readable as a watch when the chronograph is idle, and the date sits in an aperture. That is a complete specification rather than a minimal one, and it is worth noting on a reference where the dial is the expensive part, since the collection could easily have simplified the movement to protect the material and did not. The date is also positioned rather than merely included. On a dial where three openings have already been cut into stone, a fourth has to sit where the remaining material is strongest, which means the aperture position was decided by the dial rather than by the movement layout.
Four chronographs sit in the current Code 11.59 selection and they are distinguished by dial and case rather than by mechanism. This is the only one with a stone dial and the only one with set markers. The others use a black dial with a rose gold external zone in ceramic, and the Bleu Nuit Nuage 50 dial in rose gold and in steel. Across the wider collection stone dials appear on nine flying tourbillons, all of them time-only, so this reference is the single instance of a stone dial carrying a complication that requires openings cut through it. That makes the reference a genuine outlier rather than a variation, since every other stone dial in the collection sits in front of a time-only movement where the material has to survive one opening and no more. The difference between one aperture and three is not incremental, since each additional opening removes material and weakens what remains around the others.
The buyer here wants a chronograph that reads as jewellery without giving up the function, which is a narrower request than it sounds. Most set chronographs place their stones on the bezel and leave the dial alone, since a set dial and a working display are difficult to reconcile. This reference does the opposite, leaving the case entirely plain and putting the stones on the dial where they have to coexist with three counters and a date. That inversion is the argument for it. Collectors who want the setting on the outside of the watch have many options elsewhere and very few here. It is also the only chronograph in the collection whose dial cannot be replaced like for like, since a second slice would carry the same colour but not the same behaviour under light, and stone dials are not interchangeable in the way metal ones are. That is worth understanding as a feature rather than a risk, since it makes each example of the reference specific to itself in a way a metal-dialled chronograph never is. Two examples of this reference will differ slightly in how the black reads under angled light, and an owner who has handled several will be able to tell theirs apart.
