Seven grounds on this reference are set with diamonds and only three of them keep the plain ring. Aubergine, dark grey, pink and silver all receive that ring joined by gold Roman numerals at six and nine; bright black, bright blue and mother-of-pearl receive the ring alone. The division does not follow tone, since two dark grounds sit on opposite sides of it, and it does not follow saturation, since two colored grounds do the same. It was decided per ground and recorded without explanation. This variant is on the unadorned side of that line: a white mother-of-pearl dial with diamonds in gold settings at the hour positions, in a 36 mm case of steel and white gold, under a fluted bezel, on a Jubilee bracelet.
Shell is the ground with the strongest claim to being left alone, and the collection treats it accordingly. It is cut from a natural material, sliced thin and laminated onto a metal plate, and the disc has to be taken from a section free of flaws because the material splits along its own grain. Under the crystal the laminations behave as a stack of translucent sheets, so light refracts through them and returns broken into pale blues, greens and pinks that shift as the wrist turns. Numerals placed on that would compete with the effect and, worse, would sit against a background that changes from one example of the reference to the next, so a numeral falling where the nacre happens to be brightest on one watch would read quite differently on another. A ring at the perimeter avoids the problem entirely, since the outer edge of a shell disc is its most consistent region. There is a second argument for restraint that applies to this construction specifically. A steel and white gold case is cool throughout with its only precious element at the bezel, so the watch around the dial is quiet and offers no competition, and a shell surface placed inside it becomes the sole source of variation on the entire piece. Adding numerals would divide that variation rather than increase it. The collection appears to have reached the same conclusion, since every two-tone reference carrying this ground keeps the ring and only the solid metal cases elaborate it.
The plate is pierced at each hour position for the settings and nowhere else, with no second depth of fixing for numerals, which leaves more of it intact than any of the four numeral-carrying dials on this reference. That matters here more than elsewhere because shell is bonded to the plate across its whole area rather than resting on it, so the disc takes the shape of whatever lies beneath and a plate that is not flat produces a shell surface that is not flat either. Behind the dial the movement is self-winding and runs for roughly 70 hours away from the wrist, against close to 55 in the 28 and 31 mm references, since a larger case takes a physically larger movement with a proportionally longer mainspring. The date advances in a single step at midnight and the crown screws home when the watch is not being set. The aperture is the one place where the material has to be cut through rather than merely pierced beneath, and it repays attention. Opening a window in a laminated shell without chipping the edge is a different operation from cutting one in a metal plate, and the edge then has to be finished so it reads as intentional. On a dial whose appeal rests on an unbroken natural surface, that single rectangle at three is the only visible interruption, and how cleanly it is executed decides whether the dial looks made or assembled.
Where the ground does change is on the solid metal cases rather than on this one. At 36 mm in Everose, yellow or white gold, or in platinum, the shell dial takes baguette-cut stones at six and nine or baguettes throughout, and by 40 mm baguettes are the only arrangement offered. The two-tone constructions keep the ring unchanged from 28 mm upward. So the material is elaborated on the precious metal references and left alone on the mixed ones, which is the reverse of silver on this same watch, where the two-tone case gains gold numerals and the solid case moves to baguettes. Two set grounds, the same sizes and metals available to each, and opposite answers about which construction earns an addition. Reading those two grounds side by side is the most useful thing this reference offers a buyer working across the range. They occupy the same sizes, the same metals and the same bezel treatments, they are described in identical language, and they disagree about which case deserves more. Neither answer can be derived from the other and neither is stated anywhere. The only way to know what a set dial will actually look like in a given case is to check that ground in that construction.
The argument for this configuration is that it is the largest presentation of the material with nothing imposed on it. Steel case, steel bracelet, one ring of white gold at the bezel, one ring of settings on the dial, and a surface that will not be the same on any two examples of the reference. Collectors who choose it are buying the shell rather than the arrangement, and generally prefer the two-tone construction precisely because it is the version where nothing has been added. The Jubilee moves with the dial rather than against it, which suits a ground that is never quite still. Among the arrangements offered here it is the one hardest to photograph and easiest to recognize in the hand, and the only one where two owners of the same specification will not own the same watch. That is worth more to some buyers than any arrangement of markers could be, and it is the reason shell holds its position in a collection that otherwise varies its dials by adding things to them. Here the variation is in the material and nothing has been added at all.
