Sapphire crystals are a common element in luxury watches, but entire cases made of sapphire have been and remain a rarity in the watch world due to the extreme difficulty in making them (and thus, not coincidentally, their prohibitively expensive price tags). However, the most recent Swiss watch fairs have seen several brands join the sapphire-case party, each in their own distinctive fashion. Here are five that have made recent debuts.
Limited to just eight pieces and exclusive to the United States, the Greubel Forsey Double Tourbillon 30º Technique Sapphire features a solid sapphire case that has been carefully machined from a single block of sapphire crystal. The aim is to offer full visual access to the multi-level movement, with its two tourbillons, from all possible angles. The case is 49.95 mm and 17.15 mm thick, just a bit larger than those of its predecessors in rose gold, white gold, platinum and titanium. The crown, engraved with the GF logo, is also made of sapphire. The manual-wind movement, which carries an impressive power reserve of 120 hours in four series-coupled barrels, features a patented system in which an inner tourbillon, inclined at a 30º angle and making the traditional one rotation per minute, is paired with an outer tourbillon making a more unusual one rotation every four minutes. The watch (more details here) is priced at approximately $1.1. million.
The Hublot Big Bang Unico Sapphire, launched at Baselworld 2016, is an edition of 500 pieces and represents the brand’s first large-scale series of watches with cases cut from pure sapphire blocks. The middle, bezel, and back of the 45-mm-diameter case are cut from blocks of sapphire; only the screws, crown (which is overmolded with silicon) and the watch’s deployant buckle, are made from titanium. The openworked dial is made of transparent resin and shows off the watch’s movement, Hublot’s in-house Unico Caliber HUB1242, which includes an integrated flyback chronograph function, with the column wheel and double clutch both visible on the dial side. The movement has a black PVD treatment and a 72-hour power reserve; in addition to the hours, minutes, small seconds, and chronograph functions, it includes a date display in a window at 3 o’clock. The structured, lined rubber strap is as transparent as the case. The watch — which we covered in detail here — will be priced at $57,900.
The “SV” in the name of MB&F’s new watch, the MB&F Horological Machine No. 6 SV, stands for “sapphire vision.” The watch is a completely transparent version of the company’s HM 6 Space Pirate of 2014. There are sapphire plates on the top and bottom of the watch. Glued to these plates are nine sapphire domes; five on the front of the watch and four on the back. Four of the domes cover the rotating minutes and hours indications, which are made of aluminum machined to the thinness of paper. Four more cover two turbines, driven by the winding rotor (visible on the back of the watch) via a gear train designed to multiply the number of rotations. The purpose of the turbines is to slow the spinning of the rotor, via increased air friction, in case it starts spinning too quickly. This reduces wear on the rotor. The center dome covers the flying tourbillon. The tourbillon has a retractable titanium shield designed to protect its oils from being damaged by ultraviolet light. The shield opens and closes by means of a crown at 9 o’clock. The watch is a limited edition, with 10 pieces in rose gold ($368,000) and 10 in platinum ($398,000).
The movement architecture used in the Richard Mille Tourbillon RM 56-02 Sapphire takes its cues from the movement in another Richard Mille watch, the RM 27-01 Rafael Nadal, developed with the input of the Spanish tennis star. The baseplate of the RM 56-02 movement is made of tough but lightweight titanium and suspended within the all-sapphire case by means of a single-braided cable only .35 mm thick. The movement uses a system of four pulleys on posts at its corners and another six pulleys along its periphery; a miniature ratchet at 9 o’clock controls the tension of the cables. The entire system mis connected to an indicator at 12 o’clock that enables the wearer to check the tension in the pulleys to make sure its operating within the designated norms. The transparent sapphire case — which is made up of three parts, each milled and ground from blocks of solid sapphire — has a hardness of 1,800 Vickers and is virtually scratch-resistant to any material short of diamond. Sapphire is also used in movement parts, including the winding barrel bridge, the center bridges, and even the tourbillon. The “see-through” aesthetic extends to the partially translucent strap, created exclusively for Richard Mille from a proprietary Aerospace Nano material whose silky, organic texture complements the ergonomic design of the case. The watch, limited to just 10 pieces, is priced at $2,020,000. Click here for more info and photos.
The Florence-based Visconti pen maker ventured into the watch business three years ago. Within its watch lineup have been transparent sapphire-case models inspired by the brand’s “demonstrator” pens, transparent pens that pen makers supply to retailers so that they can demonstrate the watches’ inner workings. This year Visconti introduced a new so-called “Demo” watch, the Visconti 2 Squared Crystal Demo Automatic. Its case is made of a single piece of sapphire so that you can see the movement from every angle. The movement, made by Switzerland’s Technotime, has a power reserve of five days. The power-reserve display is between 4 and 6 o’clock. Between 12 and 2 o’clock there is a retro- grade date display. In addition to the red version shown here, the watch also comes in blue, smoke or colorless versions. Price: $22,500.