LE BRASSUS, Switzerland — A simple wristwatch, with a case the size of a quarter, consists of hundreds of tiny pieces, and there are people who specialize in making each and every one of them. Including the rubies.
Everyone appreciates that rubies can dazzle on someone’s neck, ears or wrist. But only watch geeks probably recognize the essential role they play in making a watch work: Hidden inside each movement is anywhere from 17 to 50 tiny rubies. They are such an important part of the watch that the number is engraved on the movement, “21 Jewels” being most common. The more rubies used, the more expensive the watch.
Those rubies are so minuscule, as small as 0.5 millimeters (0.02 inches), that magnification is required to work on them. Each tiny ruby grain must be cut and faceted in a variety of ways, each cut made for a specific purpose. Some act as shock absorbers, while others are pierced with a hole so they can be placed on an axis and reduce friction.
“Rubies are hard stones, second only to diamonds,” said Jean-Paul Dall’Acqua, director of La Pierrette, one of the leading players in the watch world’s ruby business. The company, founded in 1914 by Auguste Reymond, now has an annual output of around 50 million rubies; it won’t disclose its revenue.
It supplies the three companies that bought La Pierrette in 2000: Patek Philippe, Rolex and the Richemont group, which has nine watch houses including IWC Schaffhausen, Jaeger-LeCoultre and Vacheron Constantin. And if that’s not enough of a corner on the luxury market, La Pierrette also supplies Hublot, Audemars Piguet, Breguet, Blancpain, Ulysse Nardin and others.
La Pierrette has been processing rubies for watches for more than 100 years. “In the beginning we used natural rubies, but today you can’t find enough,” Mr. Dall’Acqua said, so the processing starts with synthetic stone supplied, in slabs, by various sources from around the world.
“The synthetics have the same qualities as natural rubies,” Mr. Dall’Acqua said. “If you want quality stones, color is important. Some Chinese stones are too pink, which is not what we request for the Swiss watch industry.” The preferred color, for aesthetic reasons, is a deep purply red, like a fine Bordeaux.
Each of the company’s 135 workers in the facility, which totals 88,695 square feet on three levels, has a specific job in the dozens of steps needed to turn synthetic rubies, each a little loaf shape about the size of a Twinkie, into watch parts. There’s slicing, dicing, drilling, shaving, filing, sorting — and polishing, polishing, polishing each and every minute ruby to be certain there are no rough spots that would create friction.
And they do almost all of it by hand, with a bit of help from some lasers.
Looking at the minuscule rubies, some with holes measuring a minute 0.07 millimeters in diameter, it’s hard to believe that the interior edges are rounded to lessen the contact points and, hence, the friction.
Or that some have an additional faceting, called demi-glace, or half glaze, that really serves “no function, it’s all aesthetic,” Mr. Dall’Acqua said. Patek Philippe orders demi-glace for the 50 rubies it uses in most of its watches because if the rubies were exposed in the movement, and if they were viewed through a microscope, and if light were shining on them at the time, the demi-glace surface might provide a bit of glimmer.
For this, Patek Philippe pays more because each processing step, of course, increases costs.
It seems an impossible task, and microscopes are essential, as are brushes and other tools of the jewelry trade. “We manufacture the tools we can’t find anymore,” Mr. Dall’Acqua said.
As for the machines — like the olivage machine, which rounds the edges of each ruby to give it an olive-like shape — “they are too specialized and complicated to find in the market, so they must be adapted or built by us,” he said.
In recent years, robotic arms and lasers have streamlined some of the dozens of steps each little ruby goes through.
The arrival of laser cutting in the 1960s had a huge impact on the stone industry. “There used to be 30,000 people working worldwide; now there are 500 in Switzerland,” Mr. Dall’Acqua said.
La Pierrette has developed a few laser machines to replace some manual processes — although, Mr. Dall’Acqua noted, many still can be done manually, and even more quickly, than by machine. But the machine can work 24/7.
Outside the room housing five laser machines is a view through the floor-to-ceiling windows of snow-capped mountains and a thick band of deep green fir trees growing up their slopes. The occasional cross-country skier glides by.
In one direction the view takes in the Vacheron Constantin factory next door; in another, the old farmhouse that was the home of La Pierrette’s director in the 1980s and ’90s. In recent decades La Pierrette had been housed in four buildings in Le Brassus; then, in 2009, the…