Emerald is the one stone in the anniversary Royal Oak gem set that is being cut against its own nature. The emerald cut exists because emerald is brittle and almost always internally fractured, and the stepped rectangle with its clipped corners was developed specifically to remove the sharp points where the material is most likely to chip during setting. A baguette is that same rectangle with the corners left on. Audemars Piguet has therefore taken the gem whose standard cut was invented to protect it and cut it in the one geometry that protection was designed to avoid, then set a full run of those stones across a dial, a bezel and an entire bracelet. Emerald is also almost never clean. The internal fracturing that gemmology calls the garden is intrinsic to how beryl forms with chromium present, and a run of baguettes that agree closely enough in clarity to sit beside one another is a selection problem before it is a setting problem.
The case is 41 mm across and 11.6 mm thick in white gold, with the octagonal bezel gem-set in baguette-cut emeralds. That height runs above the 10.5 mm the selfwinding Royal Oak reaches at this diameter, and the extra material is setting rather than movement, since each baguette sits in a channel cut into the metal with enough left beneath it to grip the stone. The eight hexagonal screw positions remain, and the run of rectangular stones breaks and resumes at each one. The dial is white gold set with baguette-cut emeralds across its full surface and carries no applied hour-markers. The stones are the dial. Only the white gold Royal Oak hands sit above them. The bracelet carries the same setting to the clasp, tapering from the case and closing on an AP folding clasp. Emerald returns less light than any other stone in the set, because the inclusions that give it depth also interrupt the path light takes through the crystal, so the dial reads as a dense saturated green rather than as a bright one. That is the characteristic quality of the material and the reason emerald has been valued for as long as it has.
The function set is hours, minutes and centre seconds. There is no date. Cutting an aperture through a continuous stone surface would break the setting at the point where the run most needs to stay whole, and on emerald in particular a cut edge introduces stress at exactly the place the material is weakest. Centre seconds keeps the three hands on one axis and avoids the second circular interruption a small seconds subdial would impose. Time is read from hand position against the case, since there are no markers on the dial. Emerald is dark enough that white gold hands separate cleanly from it in most conditions, which is an advantage this reference shares with the ruby and blue sapphire versions and not with the pale stones in the set.
The Royal Oak is the collection Audemars Piguet is built on, and the anniversary gem set is the most sustained gem-setting programme the collection has carried. Ten stones were used: emerald, tsavorite, ruby, blue sapphire, tanzanite, blue topaz, amethyst, pink tourmaline, yellow chrysoberyl and orange spessartite. Each was issued at 41 mm at this reference and again at 37 mm at 15554, producing twenty references on the same construction in two case sizes. Green is one of only two colours represented twice, by emerald and tsavorite, which makes them the single direct within-colour comparison the set offers. Two further 41 mm references sit outside the anniversary designation and abandon the single stone for graded mixtures, one of black sapphires with tsavorites and smoky quartz, the other of graded blue sapphires with Swiss blue topaz. The 15512 handles the same anniversary brief a third way, with brilliant-cut graded blue sapphires and a diamond-set bezel, and keeps the date.
This reference suits a collector who wants the stone with the longest history in the set and is willing to accept what that costs. Emerald has been mined and valued for thousands of years, it is recognised across a room in a way tsavorite is not, and it carries associations no recently discovered material can manufacture. Against that, it is the most fragile choice among the ten in practice, less because of its position on the hardness scale than because of how it fractures, and a watch with emeralds on the bracelet is an object that has to be treated as such. Anyone weighing this against the tsavorite version is choosing between the older stone and the brighter one, and there is no answer to that which is correct in general. The 41 mm size is the larger of the two the set offers, with the same stone available at 37 mm. The anniversary designation ties production to the occasion rather than to an open catalogue run.
