The Hourstriker Verdict
Personally one of the watches that really stood out to me from the recent batch of new Audemars Piguet watches launched last week was the pair of yellow gold Royal Oaks with malachite dials. Over the past two years my wife has really got into collecting watches with malachite dials, so pairing the stone with a Royal Oak is a homerun for us. It was also crazy seeing Bad Bunny wearing the smaller variant of the watch last night during the Super Bowl Half Time show!
— Peter, Editor-in-Chief
Audemars Piguet has expanded its Royal Oak Selfwinding catalog with the introduction of two new references defined by the integration of natural malachite dials encased in 18-carat yellow gold. Available in 37mm (Ref. 15553BA.OO.1356BA.04) and 41mm (Ref. 15513BA.OO.1320BA.01) formats, these timepieces represent a continuation of the manufacture’s renewed focus on hardstone dials, following the turquoise variations released in 2023. The release strategy emphasizes the organic variance inherent in mineral dials, where the distinct banded patterns of the malachite ensure that no two units are identical. This launch also coincides with a high-profile public debut, as the 37mm reference was observed on the wrist of recording artist Bad Bunny during his performance at the Super Bowl LX halftime show, signaling the alignment between the Le Brassus manufacture and contemporary pop culture figures.
The selection of malachite for these dials introduces significant manufacturing complexities that differ substantially from traditional brass or precious metal dial production. Malachite is a copper carbonate hydroxide mineral, notable for its relatively low hardness of 3.5 to 4 on the Mohs scale, which makes it particularly susceptible to fracturing during the cutting and polishing phases. To create a dial, the raw stone must be sliced into an incredibly thin wafer, often reinforced with a brass or metal substrate to ensure structural integrity before it is mounted within the movement. The green pigmentation is derived directly from the stone’s copper content; higher concentrations yield a deep, forest green, while lower concentrations result in paler, verdant hues. The banding—concentric or parallel lines of varying color intensity—is a product of the stone’s crystallization process, requiring dial makers to carefully select sections of the raw mineral that offer the most aesthetically balanced orientation of these striations.
Courtesy of Audemars Piguet
The Case and Dial
The chassis for both references is machined from 18-carat yellow gold, a material choice that provides a high-contrast frame for the deep green of the malachite. The finishing adheres to the established Royal Oak standard, utilizing a vertical satin-brushed technique across the flat surfaces of the bezel and case flanks, juxtaposed against high-polish chamfers (anglage) that define the octagonal geometry. This alternation of finishes serves a functional purpose beyond mere decoration: it manipulates light to accentuate the architectural lines of Gérald Genta’s original design, preserving the sharp, angular profile that defines the collection. The 41mm version measures 10.5mm in thickness, while the 37mm variant offers a slightly slimmer profile at 9.3mm. Both cases are equipped with glareproofed sapphire crystals on the dorsal and ventral sides, ensuring legibility and a clear view of the mechanics, and are rated for water resistance to 50 meters, a standard sufficient for general domestic exposure but not intended for aquatic sports.
The dial layout itself is an exercise in restraint, purposefully omitting the date window to preserve the continuity of the mineral’s natural pattern. Cutting a date aperture into a stone dial not only interrupts the visual flow of the banding but also introduces a potential stress point where the brittle material could crack during machining or assembly. By excluding this complication, Audemars Piguet maintains the structural integrity of the malachite while allowing the stone’s complex grain to serve as the primary visual focus. The furniture on the dial is composed of 18-carat yellow gold applied hour-markers and matching Royal Oak hands, all of which are filled with luminescent material to facilitate readability in low-light conditions. The inner bezel, or rehaut, is toned in yellow gold to create a seamless visual transition from the dial perimeter to the sapphire crystal, effectively framing the stone without introducing a discordant color.
Courtesy of Audemars Piguet
Movement Technology
Beneath the stone dials, the two models utilize distinct selfwinding mechanisms tailored to their respective case dimensions. The 41mm reference is powered by the Calibre 4309, a modern workhorse movement within the AP catalog. With a generous diameter of 32mm (14 lignes), this caliber is sized appropriately for the larger case, eliminating the need for a movement spacer ring and allowing the mechanics to fill the display back. It operates at a frequency of 4 Hz (28,800 vibrations per hour) and is comprised of 225 components and 32 jewels. Crucially, the Calibre 4309 offers a minimum power reserve of 70 hours. This "weekend-proof" autonomy allows the wearer to remove the watch on Friday evening and retrieve it on Monday morning without the mainspring depleting, a functional convenience that has become an industry baseline for modern luxury calibers.
The 37mm model is driven by the Calibre 5909, a movement based on the Calibre 5900 introduced in 2022 to replace the veteran Calibre 3120 in mid-sized references. The 5909 is significantly more compact, with a diameter of 26.2mm (11 lignes) and a thickness of just 3.9mm, contributing to the reduced overall height of the 37mm watch. Despite its smaller footprint, it maintains the standard 4 Hz frequency, ensuring precise timekeeping stability. The power reserve for this unit is rated at 60 hours, a slight reduction compared to the 4309 due to the physical constraints of the mainspring barrel size, yet still competitive within the mid-size segment. Both movements feature a dedicated 22-carat pink gold oscillating weight and display characteristic
haute horlogerie finishing, including
Côtes de Genève, circular graining, and polished bevels, all visible through the exhibition caseback.
Courtesy of Audemars Piguet
The Integrated Bracelet
The watches are secured to the wrist via the signature Royal Oak integrated bracelet, crafted from the same 18-carat yellow gold as the case. The construction of this bracelet remains a benchmark in industrial design, characterized by its tapering form and the complex interplay of its links. The intermediate studs connecting the primary links are polished, while the top surfaces are brushed, continuing the finishing theme initiated on the case. This articulation allows for a fluid drape around the wrist, mitigating the top-heaviness sometimes associated with full gold timepieces.
The bracelet is secured with a triple-blade folding clasp, branded with the AP monogram. The clasp mechanism is designed to sit flush against the underside of the wrist, reducing bulk and minimizing the risk of accidental opening. The precise machining of the bracelet tolerances ensures that hair pulling is minimized—a common grievance with metal bracelets—while the mass of the gold links provides a tactile counterweight to the watch head, stabilizing the timepiece during wear.
Courtesy of Audemars Piguet
Pricing and Market Availability
These new Malachite references are positioned at the upper echelon of the standard Royal Oak Selfwinding lineup, reflecting the premium commanded by both the precious metal construction and the gemstone dials. The 41mm Reference 15513BA.OO.1320BA.01 carries a retail price of $81,900 USD, while the 37mm Reference 15553BA.OO.1356BA.04 is priced at $75,700 USD.
While not explicitly designated as a limited edition in terms of numeration, the production volume of stone-dialed watches is naturally constrained by the scarcity of high-grade malachite suitable for dial manufacturing and the high attrition rate during the cutting process. Consequently, availability will likely be tightly controlled through Audemars Piguet’s network of boutiques and AP Houses.
Courtesy of Audemars Piguet
Technical Specifications
Case: 18-carat yellow gold case, glareproofed sapphire crystal and caseback, water-resistant to 50 m. Size: 41 mm (Ref. 15513BA) or 37 mm (Ref. 15553BA). Thickness: 10.5 mm (41 mm) or 9.3 mm (37 mm).
Movement: Selfwinding Calibre 4309 (41 mm model) or Selfwinding Calibre 5909 (37 mm model). Frequency: 4 Hz (28,800 vph). Power Reserve: 70 hours (Calibre 4309) / 60 hours (Calibre 5909).
Dial: Polished natural malachite stone dial, 18-carat yellow gold applied hour-markers and Royal Oak hands with luminescent coating, yellow gold-toned inner bezel.
Strap: 18-carat yellow gold integrated bracelet with AP folding clasp.
Price: $81,900 USD (41 mm) / $75,700 USD (37 mm).
Reference Number: 15513BA.OO.1320BA.01 (41 mm) / 15553BA.OO.1356BA.04 (37 mm).
Notes: The 37mm reference was worn by Bad Bunny during the Super Bowl LX halftime show.