Cartier gets personal

(Fortune Magazine) -- In 1889 the Maharajah of Patiala fell in love with a stone that he spotted at an exhibition in Paris. He purchased it and years later brought it to Cartier, where jewelers weaved it into a cascade of diamonds that covered his chest and weighed in at almost 1,000 carats.

That same artisanal spirit lives on in a hushed workroom a few floors above Cartier's flagship store at 13 Rue de la Paix. Here craftsmen - some trained at a special school that Cartier opened four years ago - create bespoke baubles from scratch. And in a world where luxury is ubiquitous, more and more clients are coming to the custom-jewelry unit for a design that is theirs and theirs alone. Though still tiny in relation to the company's estimated $2.5 billion a year in overall sales, the unit has posted double-digit growth for each of the past five years and is crucial to the brand's cachet.

"We've been able to attract clients because of the beauty of these pieces," says Cartier CEO Bernard Fornas, who takes this business so seriously that he personally signs the design of every "high jewelry" piece the company undertakes. "The ultimate luxury is the thing that you have that nobody else has."

Cartier creates only about 200 unique items per year; each can cost anywhere from $190,000 to more than $6 million. Cartier comes up with many of the designs itself, but one client recently dreamed up and ordered a bejeweled desk set - pen holder, scissors, paper organizer - costing millions. "You want a glass covered with diamonds? We'll do it," says Fornas. "That's what a jeweler of kings should be able to do."

Cartier isn't the only high-end company creating one-offs for weathy clients. Five others are taking advantage of the growing trend:

De Beers

The company works only with diamonds. Rubies and sapphires need not apply. Some of their latest creations use rough, unpolished stones.

Harry Winston

The place to go for rings and earrings. The jeweler works hard to make settings invisible so stones take center stage.

Van Cleef & Arpels

Known for jewelry inspired by nature. Flowers and butterflies loom large in Van Cleef's designs. The company does custom work for existing clients.

Tiffany (Charts)

Within Tiffany's annual Blue Book collection there are a few exclusive pieces, including glass brooches using a 3,000-year-old Egyptian technique called pâte de verre.

Chanel

The jeweler produces roughly 50 custom pieces a year. Designs draw from such Chanel icons as camellias, comets, and stars.