Sapphire's hardness is second only to diamond, which makes the whole top half of the case (the most exposed half) extremely scratch-resistant. This is a timepiece that will keep its good looks for a very, very long time.
While wristwatches have long featured synthetic sapphire crystals, its use in watchcases has been much more limited, and with good reason. Sapphire retains its strength at high temperatures, has zero porosity and only reacts with acids above 300°C. However, the very properties that make it so attractive as a potential case material also make it immensely difficult to work, requiring sophisticated diamond tools to machine, and then it needs to be very carefully polished to turn the naturally opaque surface transparent.
The process would have been very difficult for even a plain plate of this size, but the complex, three-dimensional form required for HM2-SV, with its bevels, mounting holes, crystal cut-outs and gasket track, pushed the extreme limits of sapphire crystal technology way beyond what was thought possible.
Surprisingly, because it is largely unseen, the sapphire is a substantial 3.6mm thick. Thanks to anti-reflective treatment on both sides - in itself no small technological feat to uniformly apply - the case becomes virtually invisible and allows for full appreciation as the eye is drawn into appreciating a myriad of sublime nuances that are revealed in the intricate movement. Eight mounting bolts, traversing the sapphire plate like pillars and passing through the bright blue gasket sealing the two case halves adds to the architectural nature of the three-dimensional case. The eye-catching blue of the gasket is echoed in the hour disk and moon phase, and also the blued 22k gold Battle-axe automatic winding rotor is arrestingly visible through the display back.
To ensure maximum light and visibility through to the movement, the two dials - minutes and date - are also in sapphire, sapphire disks lightly brushed to a perfect translucency ensuring full legibility of the polished silvered numbers while allowing maximum light through to the engine beneath.
The engine, developed by award-winning master watchmaker Jean-Marc Wiederrecht, features the world's first mechanical movement offering: Instantaneous Jump Hour, Concentric Retrograde Minutes, Retrograde Date, Bi-Hemisphere Moon Phase and Automatic Winding. One highlight (of many) of the HM2 complication is the highly energy-efficient Jump Hour/Retrograde mechanism developed by Jean-Marc Wiederrecht, which uses his exclusive (and patented) asymmetrical-tooth gear wheels to ensure high precision and play-free functionality.
While Horological Machine No2-SV is a highly engineered 21st century timepiece in every sense, the quality and execution of the hand finishing showcases the very best in traditional craftsmanship. It is craftsmanship that is brought to the fore as the sapphire case allows uninterrupted light to enter, bounce and scintillate off the highly polished surfaces and perfectly hand-bevelled edges, bringing vivacity to the rich combination of colours, materials, shapes and textures.
Horological Machine No.2-SV is a limited edition of 25 pieces only