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Royal Oak Skeleton Perpetual Calendar
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lot 32

Audemars Piguet

Royal Oak Skeleton Perpetual Calendar

This lot has a reserve price
Estimate CHF 150 000 / CHF 230 000
Starting bid CHF 120 000
Location
Office, Zurich
Reserve not met, max bid CHF 155 000
Total bids 5
Buyer’s premium will not be charged

Specification

CaseOctaganol stainless steel case, with a sapphire caseback
BraceletIntegrated stainless steel bracelet
DialSkelotonized dial with white "Chemin de fer Minuterie" 4 white indicator rings, month & leap year indication at 12 o'clock, date indication at 3 o'clock, moonphase indication at 6 o'clock, weekday indication at 9 o'clock
MovementSkelotonized & engraved rhodium-plated automatic, with perpetual calendar
Cal.2120
Ref.25829ST.OO.0944ST.01
Movement No.719***
Case No.G72*** / No 10**
D=39mm
Year2013

Condition report

Case:Good, signs of wear
Bracelet:Good, signs of wear
Dial:Very good
Movement:All functions properly
Amplitude (Dial on top/Lift angle 52):Approx 220°
Accuracy (Dial on top):Approx +2 sec/day
Box:Yes
Papers:Yes

Details 

A very rare, extremely attractive and late open-worked stainless-steel perpetual calendar wristwatch of the famous Swiss watch brand Audemars Piguet, founded in 1875. Reference launched most probably in 1996 or 1997, purchase date: 2013. Case in stainless steel, diameter 39mm, thickness 9.3mm, open-worked sapphire dial (a so-called ‘skeleton dial’) with leaf-shaped blackened gold hour and minute hands, sapphire caseback. Ultra-thin caliber 2120/2802, self-winding, partially skeletonized and engraved, self-winding rotor skeletonized and engraved in Art Nouveau style, with 21k yellow gold inertia segment, power reserve up to 40 hours. Functions – indication of time in hours and minutes, perpetual calendar with indicators of date, day of the week, month, leap year and moon phase. Royal Oak stainless steel bracelet, Audemars Piguet ‘AP’ stainless steel double folding clasp. 

Lot essay 

Audemars Piguet launched the present reference in the mid-1990s, most probably in 1996 or 1997, as a replacement for the previous Royal Oak Perpetual Calendar reference 25636 with its characteristic open-worked dial. The 25829 differs demonstratively from the 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. Phillips auctioneers reported the reference 25829 production span as being from 1996 to 2013, with 371 pieces made in stainless steel, 102 pieces in yellow gold, 174 in pink gold, 156 in platinum, a limited edition of 25 pieces in steel and platinum, and another limited edition from 2006 with 15 pieces in tantalum and yellow gold, 16 in tantalum and platinum, and 16 in tantalum and pink gold. 

The present example is powered by the ultra-thin caliber 2120/2802. 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 Audemars Piguet caliber 2120/2802 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. 

This is clearly one of the last 25820ST perpetual calendars produced by the brand, and probably the latest to pop up on the market

The characteristic feature of the reference 25829 design is its transparent dial, through which one can see the details of the complex calendar mechanism with fine haute horlogerie finishing of all parts. Of particular interest are the leaf-shaped hour and minute hands in blackened gold, which appear on the dials of men’s Royal Oaks extremely rarely. 

Clarification is needed on the fact that this example is marked with a number greater than 1000, as the total production of the steel model according to Phillips is 371 pieces. Based on Audemars Piguet case numbering practices, we may surmise that this could be a common numbering with other Royal Oak Perpetual Calendar steel references produced during that period, such as the 25820ST. The peculiarity of the present example, to which we would like to draw the collector’s attention, is the clearly very late production period, as evidenced not only by the largest serial number of the model we have ever encountered, but also by the marking of the case number from the late G series (G-722xx). This information allows us to date the production period of the present example to 2010–2013 (the watch was purchased in 2013). 

To the best of our knowledge, this is clearly one of the last 25820ST perpetual calendars produced by the brand, and probably the latest to pop up on the market (as of the end of August 2022). 

Reasons to bid 

The Royal Oak Perpetual Calendar Open-worked Ref. 25829ST.OO.0944ST.01 would be an excellent purchase for the collector who desires a distinctive wristwatch with a classic perpetual calendar complication in an open-worked execution, one which is rare for the brand. Audemars Piguet are a world-renowned traditional watch company, one of the undisputed leaders in the haute horlogerie watch market. Ref. 25829ST is a classic collector’s item, communicating a certain era in the development of the Royal Oak collection – from approximately 1996 to 2013, when the dials of Audemars Piguet’s perpetual calendars had the classic indicator of a leap year, but were 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 and attractiveness of this watch is undoubtedly enhanced by the leaf-shaped hands of the transparent dial, which is extremely rare in men’s models of the Royal Oak collection.