A platinum case with a gold dial inside it is the least obvious way F.P. Journe sold the Octa Lune, and it is the most interesting. The case is cool and gray, the dial is 18K 6N gold and reads distinctly pink, and the whitened guilloche silver sits between them holding the two apart. Nothing about that pairing is accidental. The watch was offered at 38 mm or 40 mm on the brass calibre 1300, which puts the hours and minutes off center, the small seconds at 4:30, the large date at 12 o'clock, the power reserve at 7:30 and the moon phase above. Production of the Lune in this generation closed in 2015. A collector choosing this specification was choosing against the grain of both the obvious combinations. There is no equivalent specification anywhere in the current range.
Watch metals are usually matched, and the reason is that mismatching them is difficult to bring off. Put a warm dial into a warm case and the object reads as one thing; put a cool dial into a cool case and it reads as another. Put a warm dial into a cool case, as here, and the dial detaches from the watch and becomes a separate object framed by it. That can look like an error, and on plenty of watches it does. What stops it here is the whitened guilloche silver, which occupies a substantial part of the face and belongs to neither camp. Silver treated this way reads pale and slightly cold, close enough to platinum to relate to the case and far enough from the 6N to keep it distinct, so the eye moves from the case to the silver to the gold in steps rather than jumping between two temperatures. The engine turning does further work by breaking up reflections, so the silver never becomes a bright band competing with either metal. Blued steel hands complete it with a fourth color that belongs to nothing else on the watch. The result is a dial with genuine depth to it rather than a flat two-tone, and it changes noticeably as the light does, since the gold and the silver do not brighten at the same rate. Under a lamp the gold dominates; in daylight the silver comes forward and the two sit closer together.
The large date at 12 o'clock is the loudest element on this dial and worth understanding as a mechanism rather than a graphic. F.P. Journe builds it from two discs rather than one, a tens disc and a units disc running concentrically behind a single wide aperture, which is what allows the numerals to be printed at a size a conventional single-disc date could never reach. The engineering cost is that both discs have to move together at midnight and land together, since a tens digit that lags behind its units digit by even a fraction is immediately visible across an aperture this wide. The mechanism therefore stores energy through the day and releases it in one action, throwing whichever discs need to move. Putting the whole assembly at 12 rather than at 3 or 6 is a consequence of the movement below and of the moon needing space in the upper half; the two share the top of the dial and neither is squeezed. It is also the reason the date is legible at arm's length on a watch that may be only 38 mm across, which a smaller aperture at 3 o'clock would not be. The calibre underneath is 5.70 mm high across 223 components with 30 jewels, running at 21,600 alternations per hour on a free sprung balance with four inertia weights, and the barrel gives about 160 hours.
F.P. Journe sold the Octa Lune as a set of six configurations rather than as one watch, and that matters when reading any individual example. Two case metals, platinum and 18K 6N gold, were each offered with a choice of dial, and bracelets were available in both metals alongside straps. Most buyers took the matched combinations, because matched combinations are what most buyers take. The mixed specifications went to people who had thought about it, and the platinum case with a 6N gold dial is the most emphatic of those, since it maximizes the distance between the two metals rather than splitting the difference. That has a consequence now. Matched examples turn up regularly and the mixed ones do not, so scarcity here is not a function of production limits but of what people chose at the counter twenty years ago. It also means that no two examples of this specification are guaranteed to have left the manufacture in the same year, or even in the same half of the reference's life, which is not the case with a limited run. There was no edition, no numbering and no restriction. There was simply a form with boxes on it, and comparatively few people ticked these two. Scarcity arrived afterward and by accident, which is the most durable kind.
Buy this one for the dial and inspect the dial accordingly. A 6N gold dial cannot be refinished to match, because the color comes from the alloy and any replacement surface will sit at a different point on the warmth scale; a redone dial announces itself against the case within a few seconds under daylight. Look across it at a low angle for polishing marks, for softened edges where the guilloche meets the gold, and for any unevenness in the pink. Confirm the hands are the original heat-blued steel rather than lacquered replacements, which show as flat blue without the violet. Then establish the case size, since 38 mm and 40 mm wear differently enough to be worth deciding in person. Ask what the watch has been serviced with and by whom, since a dial like this is at its most vulnerable while the movement is out of the case. Run the mechanical sequence afterward: the date throwing both discs cleanly at midnight, the moon advancing through a complete cycle, and the reserve hand descending its full travel over several days.
