Académie Horlogère des Créateurs Indépendants


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Audemars Piguet

Royal Oak Perpetual Calendar Skeleton CHF 270 000


A very rare, attractive and refined open-worked perpetual calendar rose gold wristwatch of the famous Swiss watch brand Audemars Piguet, founded in 1875. Reference launched in mid-1990s, estimated production period: mid-2000s. Case in 18k rose gold, diameter 39mm, thickness 9.3mm, transparent sapphire dial (a so-called ‘skeleton dial’), blackened gold ‘leaf’ hour and minute hands, sapphire caseback. Caliber 2120/2800SQ, self-winding, open-worked rotor with an inertial segment in 21k yellow gold, ultra-thin, with a power reserve of up to 40 hours. Functions – indication of time in hours and minutes, perpetual calendar with indicators of date at 3 o’clock, day of the week at 9 o’clock, month at 12 o’clock, and moon phase at 6 o’clock. Royal Oak bracelet in 18k rose gold, Audemars Piguet ‘AP’ double folding clasp. 


Ref. 25829OR comes up for auction very rarely and will therefore be a very attractive purchase for a collector, who will obtain a charming and very rare complicated mechanical watch from a world-famous traditional watch brand, one of the undoubted leaders in the haute horlogerie watch market. With the recent rush for Royal Oak Perpetual Calendars, this is a perfect chance for collectors to acquire a classic reference that communicates a certain era in the development of the Royal Oak collection – from 1997 to 2014, when the dial of the perpetual calendar had the classic indicator of a leap year, but was still without the central hand of the indicator of the week of the year, which is a customary feature of modern models made on the basis of clones of caliber 2120/2800. The collector’s value of this watch is undoubtedly enhanced by the transparent dial with leaf-shaped hands, which is very rare to the models of the Royal Oak collection, as well as the attractive all-rose gold execution.


Audemars Piguet launched the present reference in the mid-1990s, most probably in 1997, as a replacement for the previous Royal Oak Perpetual Calendar open-worked reference 25636. The 25829 differs demonstratively from previous 25636 models by the presence of a leap year indicator, which is made in the form of an additional small hand on the month counter at 12 o’clock. The serial-production reference 25829 exists in stainless steel; platinum (as the present reference); yellow gold; pink gold; three models combining tantalum and platinum, pink gold or yellow gold; and as a limited series of 25 pieces in stainless steel and platinum. The present Ref. 25829OR features a luxurious and splendid all-rose gold execution with rose gold case, bezel and bracelet. It is undoubtedly one of the most charming references that is no longer in production. It was succeeded in 2015 by the latest generation of 41mm perpetual calendars, featuring the number of the week indication via a special pointed hand.

The present Ref. 25829OR features a luxurious and splendid all-rose gold execution with rose gold case, bezel and bracelet. It is undoubtedly one of the most charming references that is no longer in production.

The present example is powered by caliber 2120/2802 in an open-worked version of the 2120/2802SQ. The small thickness of the movement made it possible to produce remarkably thin and elegant watches, which is especially significant given the complexity of the function of the perpetual calendar itself. With a thickness of 3.95mm, it remained the thinnest perpetual calendar movement with a central rotor of an automatic winding system until 2018. The basic automatic movement is based on a movement-blank supplied by Jaeger-LeCoultre, while the calendar module is based on a kit from the Dubois Dépraz factory. Both are long-term partners and suppliers of Audemars Piguet. 

The characteristic feature of this design is its transparent dial, through which you can see the details of the complex calendar mechanism with a fine haute horlogerie finish. Of particular interest are the leaf-shaped hour and minute hands in blackened gold, which evidently only appear on the dials of the 25829 models. 


CaseOctagonal rose gold case 750/1000 with a sapphire caseback, crown at 3 o'clock
BraceletIntegrated rose gold 750/1000 bracelet
DialSkeletonized dial with "Chemin de Fer Minuterie" 4 white indicator rings, month and leap year indication at 12 o'clock, date indication 3 o'clock, moonphase indication 6 o'clock, weekday indication 9 o'clock
MovementEngraved & skeletonized rhodium-plated automatic movement, with perpetual calendar
Movement No.638443
Case No.F38029 / No. 0066


Case:Very good, small signs of wear
Bracelet:Very good, small signs of wear
Dial:Mint condition
Movement:All functions working properly
Amplitude (Dial on top/Lift angle 52):Approx 290 degrees
Accuracy (Dial on top):Approx + 6 sec/day


We offer worldwide delivery on all of our watches.

If ordering from Switzerland or Europe, your watch will be sent the same working week. The courier will depend on the value of the watch, with all watches delivered the next working week.

If ordering from outside Europe, delivery will depend on the choice of courier and destination.

You can cancel your order without giving any reason, within 14 days from the day the watch has been delivered to you.


All of our pre-owned watches have undergone thorough mechanical inspections, including being ultrasonically cleaned, serviced and resealed if appropriate and tested for at least four days, to ensure they meet our highest timekeeping standards.

Our pre-owned and vintage watches, unless stated otherwise, are covered by a full or a limited twenty-four month warranty. For example, due to their age, some vintage watches should not be subjected to the same conditions as when they were new.

All of our new watches are covered by the warranty from the original manufacturer. Please contact us for further information.

Please see our Terms & Conditions for further information.



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