Embracing a Vintage Diamond Cutting Style

HONG KONG â€" Flat at the bottom, with just 24 facets, a rose-cut diamond imparts little of the light and fire of a modern brilliant-cut stone. But the jewelry designer Michelle Ong sees something sublime in the subtle beauty of this vintage cut and, through her company Carnet, is on a mission to popularize it once again.

This palm tree brooch with rose-cut white and brown diamonds was one of the first pieces designed by Michelle Ong for her company, Carnet. ‘‘I could only create the piece by using  rose-cut stones, as they have both a delicacy and strength,’’ she said.

Ms. Ong, the jewelry designer behind Carnet, is a champion of the traditional rose cut. She says the style has a special way of diffusing light through the gem.

Ms. Ong says that sometimes the gems themselves inspire designs, like this Dancing Acorn brooch.

“I am really attracted by the special light-diffusing elegance inherent in rose-cut diamonds. They have a mesmerizing, soft brilliance,” Ms. Ong, 55, said. “Imagine light pouring through the clearest of water.”

The designer, a longtime collector of Art Nouveau and Art Deco jewelry, started Carnet in 1990 to link high jewelry with her own female perspective on aesthetics. “I started using rose-cut diamonds over 15 years ago. Almost no one was using them at that time anymore,” she said, surrounded by the jewel box-style boutique that Carnet operates in Hong Kong’s Central district. “Rose-cut diamonds were used in absolutely wonderful old pieces, and I immediately wanted to use them in my own way for Carnet.”

The rose cut, which got its name because the facets resemble the flower’s spiraling petals, originated in the 1600s in Golconda, India. It, along with the old European mine cut, which also had a flat bottom, were popular during the Art Nouveau and Art Deco periods. But as modern cutting technology was developed in the mid-20th century, the rose cut gave way to the brilliant cut, which focuses on achieving the maximum amount of light from the diamond.

Along with Carnet, other jewelry makers also have re-embraced the classic cut. For example, De Beers Diamond Jewellers debuted its “Talisman Collection” and Tiffany & Co. recently introduced the “Tiffany Garden” collection based on botanical designs by Paulding Farnham (1859-1927), both of which feature rose-cut diamonds.

“One of the first pieces I created was a large palm tree brooch with rose-cut white and fancy brown color diamonds,” Ms. Ong said. “I wanted to capture palm leaves that had dimension and yet a graceful light-filled sensibility, as though they could really swap in the breeze, supported by the gold-bound and diamond trunk and base.

“I could only create the piece by using rose-cut stones, as they have both a delicacy and strength,” she continued. “It would not have worked with the same impact or fluidity if I had used pavé or brilliant-cut diamonds.”

However, she added, a rose-cut diamond “has fewer facets in order to obtain a marvelous, almost shimmering surface, and the depth of the cut stones can vary, making it an intensive labor to match and set up in the right way. The bigger the pieces the more challenging, since they must have the same visual surface.” She said her company often recuts stones to achieve that necessary symmetry.

Another of Ms. Ong’s showcase pieces is the “White Organdy” diamond necklace that, at first glance, might be mistaken for just some very nice crystals. But, composed of more than 2,000 matched rose-cut diamonds on an Edwardian-inspired lattice design in platinum, it took Carnet more than 10 years to complete.

Carnet’s feminine, one-of-a-kind pieces, which start at $15,000, have a loyal following with Hong Kong’s socialites and increasingly, the new rich of mainland China. They also are sold through the jeweler Harry Fane at his Obsidian gallery in London, and had a bit of big-screen fame when Ms. Ong was asked to design the “cruciform key” used in the 2006 movie “The Da Vinci Code,” starring Tom Hanks.

In person, Ms. Ong is articulate and elegant, a fixture on Hong Kong’s social scene. Her husband, a doctor, is part of the family that owns Garden Bakery, which says it supplies 70 percent of the bread consumed in Hong Kong, including all the buns used at McDonald’s.

A self-taught designer, Ms. Ong works with Avi Nagar, a diamond dealer who moved to Hong Kong 32 years ago from Tel Aviv.

“About one in 1,000 diamonds on the market today is made into a rose cut,” said Mr. Nagar, who comes from a family of diamond experts. (His father was a cutter, and his brother deals in rough diamonds.)

He sources rose-cut diamonds for the company from cutters in India, Russia, Belgium and Israel. “The circle of dealers is very small, and they know what we are looking for so they come to us,” he said.

But sometimes he purchases stones for recutting or rough stones to be handled by the 10 artisans in Carnet’s atelier in the Sheung Wan district. “Cutters who come across certain characteristics that are suitable for rose cut â€" stones that are flat and don’t have a lot of height â€" bring them to us,” he explained.

Unlike the conical brilliant diamonds, now cut by machine, rose cuts must be made and polished by hand, using saw blades and scalpel-like knives. Carnet’s craftsmen also are trained in manipulating precious metals and creating molds from Ms. Ong’s drawings, using materials like platinum, titanium and gold.

Ms. Ong said the stones themselves often inspired the final design, like they did for her Dancing Acorns brooch.

“When I saw the fancy colored rose-cut stones, I knew I would design a piece that represents this icon of nature through the icy beauty of rose-cut stones,” she said. “Sometimes it can take years to find and match just the right diamonds, but I am a perfectionist, so I always wait until everything is exactly right.”

A version of this article appeared in print on April 24, 2013, in The International Herald Tribune.