Angular Momentum company's experiments with fusing sapphire

The headquarters of the small independent sole-manufacturer Angular Momentum of Switzerland watch company is situated in the capital of Switzerland, Bern. The brand offers a wide variety of services for individuals, who want to have their own unique timepieces. Angular Momentum is now probably the only company, whose unique selling proposition is creating unique 1/1 pieces, combining fine historical movements with bespoke watch cases of any thinkable material with the widest variety of dials and medallions. Men's and women's Angular Momentum wrist watches are genuine masterpieces of high watchmaking art. No other company in the world devotes itself to the watches' beauty with the level of attention to detail, as Angular Momentum does and no other brand has ever set an aim to convert regular wrist watches into unique, unforgettable and precious works of art.
Using old traditional decorative techniques together with the newly developed ones enable the company's only craftsman, Martin Pauli, who is its owner as well, create beautiful pieces, never seen before. The rich variety of techniques, used by Martin Pauli, includes hand engraving and relief works on silver, gold, mother of pearl, camel bone, tortoise shell, porcelain and the uniqueness of the Japanese Urushi lacquer technique.
Nowadays most of Angular Momentum company's annual outcome are bespoke women's and men's wrist watches, produced in very limited editions, not more, than 350 pieces a year.
Each piece, signed, engraved, or stamped with the “manu propria” emblem is fully handcrafted by Martin Pauli. All other brand's watches are produced at Angular Momentum atelier and contain elements, brought by special suppliers, who execute such works, as hard guilloche and gem setting.

Sapphire (from the Greek “sappheiros”, the blue stone) is a gem variety of mineral corundum, an aluminum oxide (α-Al2O3). Trace amounts of other elements – iron, titanium or chromium give corundum blue, yellow, pink, purple, orange or greenish colour. Chromium impurities give corundum a red tin and the resulting gem stone is called ruby. It is produced in industrial or decorative purposes as big crystal boules. Due to the high durability of sapphire (and aluminum oxide in general), it is used for non-decorative purposes, including the production of infrared optic components for scientific instruments, highly-durable windows (used in scientific instruments as well), wrist watch crystals and movement holders. Synthetic sapphires are produced from agglomerated aluminum oxide, sintered and fused in inert atmosphere (for example, isostatic pressing), yielding semitransparent polycrystalline product, a little porous. Sometimes more traditional methods are used, such as Verneuil, Czochralski, flux method and others, yielding single crystal sapphire material, not porous and requiring internal stress defusion. The melting point of synthetic sapphire is 2050° C.

First time ever for decorative usage

During the last months Angular Momentum has performed lots of experiments with fusing sapphires of different colours on watches' transparent sapphire crystals or dials. The process can be compared to the classic vitreous enamel application technique, when glass powder is fused on a substrate, such as gold, silver or copper at the temperatures between 750 and 850° C.
Taking into consideration, that synthetic sapphire's melting point is 2050° C, it's impossible either to fuse it on a substrate or to use the thin lines, used for barriers building with several zones for further enamel application, used in the Cloisonné technique.
Swiss wrist watches of the “Fusion” series from Angular Momentum demonstrate humble, yet enchanting results of the first experiments. At the next stage the company promises to experiment with a kind of Champlevé, which means a “raised field” in French. When you use this technique, several pits, filled with sapphire are craved in the surface of the watch, which are then fired, leaving the original material exposed.