Over all, the luxury jewelry market is expected to reach $37.8 billion in 2017, and grow by an average of 2.1 percent annually over the next four years, according to the market research firm Euromonitor International.
One key growth factor, Mr. Timelin said, is a projected surge in the number of millionaires to 56 million in 2025, from 25 million in 2015. “A large chunk will come in the U.S.,” he said.
As a result of the optimism fueled by such forecasts, the high-end jewelry business — which remains largely unorganized and therefore ripe for brand consolidation — is attracting newcomers enchanted with its potential.
The Mumbai-based Nirav Modi introduced his high-jewelry brand in 2010 and now has eight boutiques around the world, including stores on luxury main streets in New York, Hong Kong and London. In 2017, Mr. Modi said, he plans to open 10 more boutiques in markets where he sees promise, including India, greater China, the United States and Europe. He has vowed to have 100 stores by 2025.
Mr. Modi says that while sales of one-of-a-kind jewels are fueling his growth, so, too, are midprice jewels (which cost from $10,000 to $50,000), a point echoed by many of his peers in fine jewelry.
“The jewelry that is increasing its performance is the accessible jewelry, in terms of number of pieces but also in terms of sales,” said Karl-Friedrich Scheufele, co-president of Chopard, a luxury watch and jewelry brand based in Geneva. “Jewelry pieces are conceived not as once-in-a-lifetime investments or special-occasions gifts but more like expensive fashion accessories.”
To understand that phenomenon, consider two developments that have transformed the jewelry industry over the last decade.
The first is a replay of what happened to the fashion business 25 years ago, when brands began to dominate a landscape once ruled by a global coterie of mom-and-pop boutiques, said Thomas Tochtermann, an independent adviser to fashion and jewelry companies who is based in Hamburg, Germany.
“Clients are more global and are gradually moving from the family jeweler to global brands,” said Jean-Christophe Babin, chief executive of Bulgari. “Because you need trust, you need ethics. If you don’t know the jeweler around the corner, you don’t necessarily trust him.”
The second factor reflects the growing importance of design. Unlike in the 1980s, when buyers were “really concentrated on traditional diamonds and stones, and not so much on creativity,” recognizable design is making a comeback, said Nicolas Bos, chief executive of Van Cleef & Arpels.
He referred to “narrative jewelry,” or pieces that tell a story, and to a growing appreciation for a much wider spectrum of stones, including semiprecious gems, as dynamics shaping the world of high jewelry.
Although Mr. Bos didn’t mention the M-word, it’s clear that the millennial generation’s views on adornment weigh heavily on the category.
“The key word is ‘wearable,’” said Ward Landrigan, chairman and chief executive of the fine jeweler Verdura. “I started in this business in New York at the end of 1964 and, for a long time, the big glamour of the major emeralds, rubies, diamonds — the great big pieces — is what people aspired toward. Now it’s a different generation. People making the big money today don’t show it off the same way. They want pieces you can wear and not look like Queen Elizabeth. They don’t even aspire to that big look.”
This is just as well, given that makers of the most elaborate and expensive jewels — the cost of which is almost always driven by the size, quality and availability of the gemstones — may find supply to be their biggest challenge.
“If we consider the top end — anything, I would say, above $500,000 — it’s a market that grows but can only grow so much,” Mr. Babin said. “Because the gems in that segment are so extraordinary.”
Just ask Chopard. At an event in Paris in January, the brand unveiled a suite of 23 flawless diamonds — including five weighing more than 20 carats each — cut from a 342-carat rough stone nicknamed the Queen of Kalahari. The firm sourced the D-flawless diamond directly from the Karowe Mine in Botswana through a unique partnership with its owner, the Lucara Diamond Corporation, and made a documentary film tracing its journey from the mine through the cutting and design processes.
At the Oscars in February, the actress Charlize Theron wore a pair of mismatched earrings weighing more than 50 carats from the resulting jewelry collection, named Garden of Kalahari. She was not the first person to stake a claim on the diamonds.
“We already have requests for the big pieces,” said Caroline Scheufele, Mr. Scheufele’s sister and co-president. “But it’s my wish that they stay together because it’s a very special story. Maybe for some generous husband or someone who has three of four daughters?”