This is the only place a shell dial sits on a white gold Day-Date at this size without stones around it. The metal supports two references at 40mm and the other one carries a set bezel, so every ground on the roster exists in exactly one configuration where nothing outside the dial is set. Mother-of-pearl is the ground that gains most from it. The material is already doing something with light, and a fluted ring answers with a moving broken brightness rather than a fixed one, so the bezel and the dial work in the same register instead of the perimeter holding still while the middle shifts.
The material is the inner layer of a mollusk, sliced thin and laid over a base rather than applied as a finish, its stacked platelet structure splitting light as it passes through them and returns. The ground drifts between white, cream and pale green as the wrist turns and never settles, and every slice carries a figure belonging to it alone. White gold is the case that interferes least. The metal reflects close to neutral and adds no tone of its own, so the shell shows what it actually is rather than what a warm case makes of it, and the pale greens that yellow gold suppresses stay visible here. The markers are baguette-cut stones running the whole way around, identical in cut, length and orientation and laid flat rather than raised, returning light in broad planes from a single angle while the ground scatters it unevenly across a curve. Nothing accents six or nine, so the dial carries no axis and the figure in the material is the only thing on it with direction. The case is 40mm with the flat wide lugs and low band the model uses throughout, and the President bracelet closes it in polished semi-circular links. Seating stones in a shell dial is harder than seating them in brass. The layer is thin, brittle across its structure and unforgiving of pressure, so each setting is carried by the base beneath rather than by the shell itself, and the openings for them are cut before the slice is mounted. A ring of identical baguettes makes that work more predictable than a mixed arrangement would, since every seat is the same shape and the same depth from one position to the next, with no larger settings needing deeper seats at six and nine.
Because the hour ring carries no accent and no gold, the two calendar openings are the only irregular shapes anywhere on the dial and the eye finds them without sorting them from competing features. The day is spelled out in full at twelve in words rather than reduced to three letters, which fixes the arc's width across every reference in the model, and at this diameter the arc takes proportionally less of the slice than at 36mm, so more of the figure survives the cutting. Both openings are framed, since an unframed edge would show the laminate in section and a flat printed disc needs a firm boundary against a surface that will not hold one value for it to match. Both discs advance instantaneously at midnight rather than turning through the hour before, the movement runs roughly seventy hours off a full wind, and everything is set through the crown alone. The hands carry more of the legibility here than they do on a flat ground. Polished white gold against a surface drifting between white and pale green can fall to low contrast at some angles and stand clear at others, so their taper and the cut of their faces matter, and they read best when they cross the darker part of the shell. On a cool case with no gold anywhere on the dial, they are also the only warm-toned element the watch does not have.
White gold at 40mm carries eleven grounds, the platinum roster with ice blue and its set version removed, and the same relationship holds at 36mm, which makes ice blue the whole of what separates the two cool metals anywhere in the model. Mother-of-pearl is one of only four grounds shared between white gold's two diameters, alongside white, blue ombre and the paved dial with sapphires; everything else belongs to one size or the other. Of those four it is the only one with enough character of its own for the change in size to be visible in it, since white looks the same everywhere and the paved dial removes the dial from the comparison. The marker arrangement is fixed here, as it is on every ground this roster carries, because the framed treatment exists at 36mm and nowhere larger. The grounds this metal gains at the larger size explain the rest of the roster's character: meteorite, silver set, olive green, slate, bright black in both forms and bright blue. Almost all of them are dark, crystalline or muted and none is a pastel, so white gold at 40mm is a considerably more sober proposition than the same metal at 36mm.
An unset bezel on a cool case is the least crowded setting the model offers a shell dial, and it is the configuration to choose if the material is the reason for the watch. Everything else on the piece is neutral and fixed. The case adds no color, the bezel adds no brightness beyond what its facets catch, and the bracelet is plain, so the dial is the only element with any movement in it and has nothing to compete with. On the set-bezel reference the same slice has to hold its own against a continuous ring of stones, and it can, but it stops being the only thing happening. For a collector who wants mother-of-pearl read as a mineral surface rather than as one decorated component among several, 228239 is where white gold puts it. It is also the quieter of the two white gold references in every respect except the dial, which is the only place the watch asks for anything.
