The URWERK UR-101 Diamond Sky is unveiled as a 25-piece limited edition that managed to catch me off-guard. I have followed URWERK’s work since 2003, and yet this piece opened a door I hadn’t expected them to push through. It is the brand’s most committed foray into gem-setting within the UR-101 architecture, and it works convincingly.
A Constellation Carved in Steel
The dial here isn’t a dial in any conventional sense. URWERK mechanically engraves the upper surface of the steel case with a geometric network of intersecting lines, and at each crossing point sits one of the 214 D-E-F VVS responsibly sourced diamonds totalling 1.63 carats. The stones follow a hexagonal arrangement across the entire field, and Martin Frei, URWERK’s artistic director, draws a direct connection to the structural logic stars maintain in space. As the wrist moves, the light fragments and scatters across the field, producing the impression of a sky in perpetual motion. The hour and minute markers carry a coating of Super-LumiNova for legibility after dark, and URWERK covers the assembly with a glareproofed, metallised sapphire crystal that adds a further layer of tonal depth to the view.
Calibre UR-1.01V: Two Satellites, One Spectacular Hour
The wandering hours complication operates on two satellites, each carrying hour numerals, that travel along a 180-degree arc from left to right across the engraved surface. At the end of each hour, a super flyback mechanism engages and snaps the outgoing satellite back whilst the incoming one simultaneously completes its rotation to take position, completing the handover in under one second. It is a mechanical event that still stops me every time I watch it happen in person.
URWERK constructs the calibre UR-1.01V from copper, brass, and ARCAP P40, and that last material deserves particular attention. ARCAP P40 is a copper-nickel alloy that is fully non-magnetic and considerably more stable and corrosion-resistant than conventional brass, making it an ideal choice for components built to tight tolerances over decades. The movement beats at 28,800 vibrations per hour (4 Hz), counts 28 jewels, and offers a 48-hour power reserve. For finishing, URWERK applies snailing to the rotor, sandblasting across the plates, satin-brushing on the bridges, and chamfers each screw head individually. That is a serious finishing programme for a movement that already asks a great deal of its makers.
The 41 mm Steel Case
The case measures 41 mm in diameter and 9.33 mm in thickness, proportions that keep the watch perfectly wearable given the complexity underneath. Steel is the material of choice, and its relative austerity creates an intentional contrast with both the depth of the engraving and the intensity of the gem-setting. URWERK places the crown at 12 o’clock, a signature position that traces directly back to the original UR-101 of 1997, and which defines the watch’s silhouette from across the room. Angular lugs reinforce that identity further. Water resistance reaches 30 metres (3 ATM). URWERK supplies the watch on a textured white rubber strap lined in black calfskin, secured with a steel pin buckle.
25 Pieces, One Genuine Opportunity
Felix Baumgartner has always described the UR-101 as the point where everything emblematic of URWERK began. The Diamond Sky edition does not revisit that starting point nostalgically. Instead, it extends the original idea into territory the brand has never occupied before, where watchmaking mechanics engage in direct dialogue with the art of jewellery. URWERK produces roughly 150 watches per year across the entire catalogue, so 25 pieces of this particular edition puts the scarcity in sharp focus. The price sits at CHF 85,000 excluding taxes. For a collector who understands both the satellite complication and the discipline of responsible high-grade gem-setting, the UR-101 Diamond Sky presents a genuinely compelling case.
