In Résonances de Cartier, the house's most recent high jewellery presentation, the diamonds, emeralds and rubies that are de rigueur in such collections were combined with more unusual materials like smoky quartz and fire opals.
But it was a black jasper cuff, carved in a classic Panthère style, that would catch the discerning eye. It was the work of a glyptician, or gem sculptor, a highly trained artisan who turns rough stone or jewels into dazzling art.
Turning the common into extraordinary
"Black jasper per se is not rare or precious," said Philippe Nicolas, Cartier's in-house master glyptician, whose atelier designed and sculpted the bracelet. It was difficult to find two large homogeneous pieces of jasper, but the human skill used to create the cuff was what made the piece valuable, he said.
Such skilled artisans also made the delicate red and white flowers adorning the black dials of the watch that Chanel displayed at Baselworld early this year, and the white petals of chalcedony on brooch in Chaumet's Hortensia collection.
The art of glyptic, using intaglio and relief techniques, is an ancient skill, well known among the Greeks, the Egyptians and others in the Middle East. It was used in making cameos, popular during Roman times and the Renaissance and again in the 19th century, and it still inspires some contemporary creators like the Serbian-American designer , whose jewellery includes an eye sculpted in Brazilian agate, and , an American designer working in Paris, who features classic cameo motifs like landscapes and profile portraits on her pieces.
The Munich-based jewellery house inserts old cameos into modern jewels because "in the olden days, sculptors looked at the stone in a more artistic way, asking themselves how to maximise beauty," said Christian Hemmerle, a member of the fourth generation to work in the family business.
Hemmerle also offers some sculpted objects in crystal. But, when asked, "Who was the glyptician?" Mr. Hemmerle, like many others in the business, answered, "I cannot reveal my sources."
Few glypticians are known to the public; most work behind the scenes, hired by houses when their particular skills are needed. The houses will not identify them, worried about the lure of rivals, and over generations the glypticians themselves have become distinctly reticent. Discretion is now the prime directive.
"Glypticians really are the unsung heroes of jewellery," said Claudia Florian, a consulting director at the Natural History department at Bonhams auction house. "The majority of them don't even sign their work."
Value added art
Ms. Florian said glypticians like Gerd Dreher or Manfred Wild had made their names by crafting animal sculptures, usually private orders. These masters are able to obtain the best raw materials and command prices that, she said, can rise to as much as three times the value of the stones they use.
In addition to the Idar-Oberstein area, glypticians also can be found in other regions rich in stone or gems that can be carved. Ms. Florian said that, for example, carvers have been emerging in Brazil thanks to the country's abundance of agate and tourmalines.
And Tarang Arora, creative director at Amrapali, said he selects carvers from Jaipur, which has had a gem-sculpting tradition since Mughal times.
China also has a rich history of glyptic art – some of which was showcased in a recent exhibition at the Metropolitan Museum of Art – as well as many artisans now working in the trade. , a sculptor who now designs jewelry in the Netherlands, described how she travelled to a remote Chinese village ("I can't tell the name of the village") to find artisans skilled in working mammoth bones for her creations.
A stone's identity
Every material requires specific training, as well as specialised tools, said , the Hong Kong-based master jeweller. Like many glypticians, Mr. Chan makes his own tools: "I even have sometimes to build the machines first in order to build my own tools."
The glyptician's approach to work provides another key to understanding the skill. "You need to forget about your own breathing," Mr. Chan said, "and when you have concentrated and forgotten to breathe is when you realise what you have been able to do."
It was that kind of rigorous focus that several years ago prompted Mr. Chan to stop trying to train apprentices. He now puts all his energy into making as many pieces of jewellery as possible, hoping to inspire other carvers.
Passing on the knowledge
In contrast, Mr. Nicolas of Cartier is committed to teaching his three apprentices at his atelier on the Rue de la Paix in Paris, not far from the haute joaillerie centre of Place Vendôme.
His specialty is a distinctive silky finish to carved stone: "I do not polish the stones," he said. "I make them softer." (He gently rubs the stone with little wooden batons, although he sometimes uses diamonds, iron, brass or carborundum, also known as silicon carbide.)
Mr. Nicolas, a graduate of the École Nationale des Beaux-Arts, spent 20 years working exclusively for Joel Arthur Rosenthal, the Paris-based jeweller known as JAR, from his independent atelier at Place Vendôme, where later one of his clients was Victoire de Castellane, creative director of Dior's fine jewellery division.
But one afternoon in 2008, during the height of the global downturn, two of his major clients cancelled all their commissions. A worried Mr. Nicolas asked to meet with Bernard Fornas, then the chief executive of Cartier; six months later, he opened his own atelier within the company.
Mr. Nicolas recalled telling the Cartier executive, "If a big jewellery house like Cartier doesn't commit to the preservation of this art, all this will be lost."
Now, almost 10 years later, Mr. Nicolas said that art is still what he wants "to keep, perpetuate and transmit."
The New York Times