This is the only mother-of-pearl configuration on a warm case where nothing warm touches the dial. Every marker is a baguette-cut stone set directly into the shell, with no gold surrounds, no accents at six and nine and no framing of any kind, so the yellow gold stops at the edge of the dial and does not continue onto it. The alternative arrangement, offered on this same reference, sets the hours into gold and carries the case metal inward. The difference between the two is larger on gold than it is on platinum, where the surrounds are a foreign element either way. Here one version extends the case and the other refuses it, and they end up looking like different watches.
Mother-of-pearl is the inner layer of a shell, cut into a slice thin enough to serve as a dial and laid over a base rather than applied as a finish. Its structure is a stack of microscopic platelets that split light as it passes through and returns, which is why the surface never settles on one value and moves between white, cream and pale green as the wrist turns. Every slice is cut from a different part of a different shell, so the figure running across this one, whatever bands or swirls it carries, belongs to it alone. The stones are uniform in a way the ground is not. Identical in cut, length and orientation, laid flat rather than raised, they return light in broad planes from a single angle while the shell scatters it unevenly across the whole surface, and that difference in the character of the light is what separates the ring from the field. Nothing accents the arrangement, so the dial has no axis of its own and the figure in the shell is the only thing giving it direction. The case is 36mm in yellow gold, the bezel is set with diamonds around its circumference, and the President bracelet closes it in polished three-piece links. Seating stones in a shell dial is harder than seating them in brass. The material is thin, brittle across its layers and unforgiving of pressure, so each setting has to be carried by the base beneath rather than by the shell itself, and the openings for them are cut before the slice is mounted.
A uniform ring of stones changes how the calendar is found rather than how it works. Because nothing in the hour ring is accented, the two openings are the only irregular shapes anywhere on the dial, and the eye goes to them immediately instead of sorting them out from competing bright features. That is a real advantage on a ground this active. The day is written out in full at twelve rather than shortened to three letters, which is what the model exists to do and what fixes the width of the upper opening, and the date sits at three under a lens set into the crystal. Both openings are framed, partly because an unframed edge would show the shell in section and partly because a flat printed disc needs a firm boundary against a surface that will not hold a single value for it to match. Both discs jump instantaneously at midnight rather than turning gradually through the hour before. The movement runs about seventy hours off a full wind, and everything is set through the crown alone. Eight grounds are built at this reference and mother-of-pearl is one of two listed in two marker arrangements, the ten baguette cuts here and a framed set with baguettes at six and nine, champagne being the other.
Mother-of-pearl set with diamonds reaches all four case metals and both case sizes, one of only three grounds in the model that does, and the other two are white and the paved dial. The marker treatment is where that reach ends. At 36mm both arrangements are offered on every reference in every metal; at 40mm the gold-framed version disappears completely and this one is the only mother-of-pearl available. So the all-baguette dial is not simply the cooler of two options but the arrangement the model carries at every size it makes. Within yellow gold at this diameter the field is three references, 128238 with a fluted bezel, 128348RBR, which splits again on the bracelet, and this one, with identical dials across all of them. Mother-of-pearl is also one of exactly three grounds on this case offered in more than one marker treatment, alongside champagne and white, so it belongs to a small group where the buyer gets a second decision after the ground is settled. Doubling of that kind is scarce here. Bright green, carnelian and dark grey are each fixed in a single arrangement with no alternative at any size or on any metal. The paved dial has its markers set by the case size rather than offered as a choice. Green ombre is Roman only, as every ombre in the range is. So across ten grounds the buyer gets a second decision three times, and the three are not equivalent: on mother-of-pearl and champagne the difference is whether gold appears on the dial at all, while on white it is only the shape of the markers.
Removing the gold is what makes this the interesting version on a yellow gold case. The watch becomes a warm object with a cool dial set into it, and the only continuity between the two is the bezel, which is set with the same stones as the hour ring. Collectors who want a gold Day-Date that does not read as a gold watch usually arrive at dark grey first and end up here instead, because mother-of-pearl gives the same temperature contrast without the flatness a grey ground carries. It also changes through the day in a way no lacquered dial can, going nearly white indoors and opening into color under a window, so the contrast with the case is stronger in some light than in others. For a buyer who already owns a yellow gold Day-Date with a warm ground, this is the configuration that will not read as a second version of it, and the difference is legible without anyone needing to look closely.
