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, recent years have seen several brands join the sapphire-case party, each in their own distinctive fashion. Here are six that have their made debuts in recent years.
1. Bell & Ross BR-X1 Tourbillon Sapphire
The Bell & Ross BR-X1 Chronograph Tourbillon Sapphire boasts a skeletonized movement equipped with both a flying tourbillon and a monopusher chronograph. Its transparent case measures 45 mm in diameter and is cut from six blocks of sapphire, one each for the case middle, back, bezel, crystal, and bumpers. Sapphire is the second-hardest material on Earth — only diamond is harder — and almost entirely scratch-proof, and the process by which it is made into a finished watch case is extraordinarily difficult, involving many hours of machining and polishing. Elements of the manually winding movement that are visible through the open dial include the column wheel, which drives the chronograph, at 12 o’clock; a hand-type power reserve indicator at 9 o’clock; the monopusher rocker that controls the chronograph’s start, stop, and reset functions; and the large flying tourbillon cage, enhanced by Bell & Ross’s ampersand logoform, which occupies the spot at 6 ‘clock. More details here.
2. Blancpain L-Evolution One-Minute Flying Sapphire Carrousel
This timepiece from Blancpain‘s avant-garde L-Evolution collection boasts not only a dial, caseband, and caseback made of sapphire, but also sapphire components in the manual-wound movement, Blancpain’s in-house Caliber 22T. Among the highlights of this movement are the nanotechnology-inspired finish on the upper bridge, its lengthy power reserve of 120 hours, and its use of a carrousel regulating system, a device that has become a hallmark of Blancpain’s haute horlogerie timepieces (for an explanation of the differences between a carrousel and its more popular cousin, the tourbillon, click here). The L-Evolution One-Minute Flying Sapphire Carrousel’s case, which marries the sapphire parts to a tantalum bezel and white-gold lugs, measures 43.5 mm in diameter and is water-resistant to 30 meters. It is mounted on a black Mississippi alligator leather strap.
3. Greubel Forsey Double Tourbillon 30º Technique Sapphire
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 $1,150,000 (July 2017).
4. Hublot Big Bang Unico Sapphire
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 — is priced at $57,900 (July 2017).
5. MB&F Horological Machine No. 6 SV
The “SV” in the name of 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, July 2017) and 10 in platinum ($398,000, July 2017).
6. Richard Mille RM 07-02 Pink Lady Sapphire Automatic
Richard Mille takes aim at sophisticated ladies with its RM 07-02 Pink Lady Sapphire Automatic watch, named for the famous cocktail introduced in the 1930s and boasting a tripartite case made of pink sapphire. The case components all are milled from a single block of the colored sapphire, and each completed case, with its curved ergonomic shape and its dimensions of 46.75 x 32.9 mm, requires nearly 40 days of machining and finishing. Inside the watch, and behind its central dial made of onyx and surrounded by diamonds, is an automatic, skeletonized movement, Richard Mille’s Caliber CRMA5. The movement’s bridges are made of the same 5N rose gold as the dial’s flanges and the winding crown, and their hand-chamfered angles and edges reflect light in a manner that draws attention to the skeletonized, microblasted mainplate. On the reverse side and visible through a clear caseback is a variable geometry rotor, also made of rose gold and also set with diamonds. The fast-rotating barrels holds a power reserve of 50+ hours. The watch is finished off with a white alligator strap.
7. Visconti 2 Squared Crystal Demo Automatic
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.