It may seem logical that an industry that relies on female consumers would be led by women, but that is not the reality in jewelry.

“Women are at the front end of it, but the heart of it is very male-dominated,” said Thelma West, a gemologist and jewelry designer in London. “It’s changing — we’re all doing our bit to make it change, but it’s been very slow. It hasn’t always been a pleasant experience in that department. But the positive thing is, more women, and also more people of color, are now doing more diverse roles in the industry.”

Here are the stories of five women, including Ms. West, now at the heart of the industry.

Thelma West

Gemologist and jewelry designer, London

Ms. West grew up in Lagos, Nigeria, where jewelry played an important part in her life. “Lagos is a very colorful city,” the 38-year-old designer said. “One way women and men express themselves is through jewelry, in different colors and styles.”

She especially loved going to the gold markets with the women in her life, primarily her mother and one of her six aunts: “I used to be fascinated watching those very traditional women who loved this idea of gold and gemstones.”

Ms. West went on to study in Antwerp, Belgium, the world center of diamond processing. “For me, diamonds are incredible because I always felt a connection to them,” she said.

In 2008, she founded Yeraua, a diamond wholesaling business; in 2012, her own brand; and in 2015, IGR London, which markets itself as the world’s first female-run diamond gemological lab.

Ethically sourced diamonds are at the center of her creations, Ms. West said, but she also uses precious gems such as emeralds, sapphires and rubies. To honor her heritage, a share of her proceeds — although Ms. West declines to specify the percentage — is divided between two Lagos-based projects: one that funds urgent medical treatment for children and the other, which funds education for girls.

“I bump into gemstones just like I bump into people,” Ms. West said in describing the way she works. “Gemstones, like people, are different: never perfect, diverse, quirky, surprising, asymmetrical and fluid. That’s the essence of what I thrive on.”

An example of her creations is the Rebel Black ring, which Rihanna wore to the 2021 Met Gala in September and was featured in Sotheby’s “Brilliant and Black” selling exhibition last fall. Ms. West said she created it after encountering an unusual pear-cut diamond. “I found it so gorgeous and very tempting,” she said. “I started to obsess about how I’d create something that would fit this five-carat misfit.”

She said she initially designed it for a well-traveled client. “I thought I’d set it in a dramatically dark black setting, something that would fit this unique woman’s personality. After I finished the design, I looked at it and it had this no-messing-around, troublemaker air to it,” she said, referring to the gem’s name. “That’s how I work. I create for one woman, but eventually it ends up with another one and fits right with her personality.”

Ms. West and her team of female professionals now craft custom pieces from a studio in London’s Soho area. But “at the beginning, I used colleagues and friends to front me in the industry,” she said. “I knew if I showed my face, the mood would change. I tell women they’ve got to have thick skin in order to exist in some worlds.

“It won’t last forever. It will change, and we have to keep pushing for change,” she added. “‘I’m here to stay, I’m here to thrive, I know where I’m going’— that sort of attitude is what will get you far.”

Joanna Gong

Private sales director and jewelry specialist, New York City

Ms. Gong’s work, even during the pandemic, has had her shuffling among cities all over the world to hunt for pieces, visit trade shows, meet with clients and even go into stone mines. Although living out of a suitcase has made it hard to establish roots, she said she considered her job as a private sales director and jewelry specialist at Sotheby’s to be a tremendous privilege.

“The world is so large, but it gets smaller every day with all the people I meet,” said Ms. Gong, 27.

“Ultimately we’re people specialists, that’s how I like to see it,” she said. “We establish trusting relationships with our clients, and we end up being the touch point for all their needs, cross-category.” In her case, she works as a specialist in gems and as an appraiser, with Uniform Standard of Professional Appraisal Practice credentials, and also handles private sales.

Ms. Gong was born in Seattle, moved with her family to Beijing when she was 6, then returned to the United States for high school. As a girl, she was drawn to the arms-and-armor collection at the Metropolitan Museum of Art in New York City. “Even if it wasn’t considered jewelry, my first love in metal crafts was a wearable piece of metal, tied to the function of the body,” she said.

She graduated from Pratt Institute in New York City with a Bachelor of Fine Arts degree and studied at Musashino University in Tokyo, where she apprenticed with the Japanese silver master Hiroshi Suzuki. She also backpacked around the world, learning about gem mining in Myanmar, the emerald trade in Colombia and gemstone-cutting in Thailand. “Even if I didn’t dedicate decades to it,” she said, the experience gave her “a better firsthand understanding of the process in order to speak about it with more authority to my clients.”

Before starting her job at Sotheby’s in early 2019, Ms. Gong worked as a private jewelry consultant and dealer, where she became acquainted with jewelry pricing and market movement, topics that she said helped her now. “Primarily it’s a market geared towards a female consumer, yet the people who control the other side of the industry are, in the majority, men,” she said. “There’s a disconnect with those on top and the product presented to the consumer, a lack of a dialogue. But hopefully in the future there will be more female executives, dealers and designers.”

Misaki Ito

Author and jewelry stylist, Tokyo

When Ms. Ito worked in Florence, Italy, about 30 years ago, she was shocked to see how Italians wore jewelry in their daily lives. It was so very different from the Japanese, she said, who reserved jewelry for special occasions, like the strands of pearls that women traditionally wore to weddings or funerals.

“I admired the way young and older Italian women looked confident wearing jewelry against their sun-tanned skin, how they enjoyed layering pieces without worrying about scratches,” she said. “I was also surprised to see that not only women but also men were interested in jewelry.”

“I wanted Japanese women to be able to wear jewelry like this,” said Ms. Ito, 64.

When she returned to Japan and started working as a freelance stylist for local fashion magazines, she pitched an idea for a feature article on women buying jewelry for themselves. “It was rejected,” she said. “I insisted that women should be able to buy what they want with their own money, but that wasn’t accepted at the time.”

She thinks that Japanese people’s ideas about jewelry have changed over the past few decades, including what to buy: “Jewelry from foreign brands is still popular, but there are more and more Japanese designers, such as Yuta Ishihara.”

And, she said, Japanese men are growing more interested in jewelry. “Recently, thanks to the collaboration between Mikimoto and Comme des Garçons, men are becoming less opposed to wearing pearls. Jewelry is now becoming a means of self-expression. It’s no longer about being a woman or a man.”

In 2019, she published a book in Japanese, illustrated with photos, on how to select and wear jewelry of all kinds. She now works as a stylist for popular Japanese fashion magazines such as Crea, Very Navy and 25ans and as a creative director for the Mikimoto look books.

“In the industry I’m working in now, being a woman is not a disadvantage,” she said. “Most of the jewelry and fashion press is made up of women. The upper echelons of Japanese publishing companies may be dominated by men, but the chief editors of women’s magazines are almost all women. I think it’s because women’s sensibilities and opinions are respected.”

Hind Laoui

Artistic director, Paris

Part of Ms. Laoui’s job as an artistic director and photographer for the jewelry brand Persée involves orchestrating photo shoots around the world, such as one last year in Mexico that involved a model, draped in layers of dainty diamond necklaces, astride a horse.

Ms. Laoui, 30, joined the brand right from the start, when her sister Nawal created it in 2017. Diamonds that appear to float free of settings are at the heart of the Persée concept, but the sisters also offer bracelets that are welded on as a sign of commitment and have operated piercing bars. “We manage the artistic direction internally, from A to Z, that’s also our strength,” Ms. Laoui said. “I have complete freedom, and the blindfolded trust the creator has in me is a huge asset in my creative process.”

She studied at Studio Berçot in Paris, a private styling and fashion institute, and spent time as an assistant on fashion photo shoots. “That is also where I learned about lighting, essential to me for a superb image regardless of the technique or the camera,” she said.

“My goal is to introduce a new beauty to the world, and photo shoots are my favorite part; it’s where I transcend the most my creativity,” Ms. Laoui said, adding that she sees them as a show, with herself as the director. That process includes video these days. “This artistic job has evolved a lot,” she said. “The technique is no longer an obstacle and today this helps us to give unlimited freedom to our imagination.”

With brand boutiques and outlets across the globe, including the Middle East and Asia, Ms. Laoui has to adjust campaigns to each market while preserving the original idea. “We always have to find unique ways to reach our target and attract their attention,” she said, “and it’s important to acknowledge and understand their identity before trying to sell ours.”

Jill Heller

Vintage jewelry consultant and curator, New York City

Travel and the study of art history helped shape Jill Heller’s fascination with vintage jewelry. “I developed an obsession with pieces from earlier periods, that are unique and hard to find,” she said. “Wearing them is like wearing art. They’re timeless.”

“Every piece comes with a story, a reason why it was purchased,” said Ms. Heller, 49. And when she finds that perfect vintage piece for a client, “we hand it down and continue the legacy.”

As a collector, dealer and curator, her job title could also be treasure hunter. Over the years she has gathered a collection that includes vintage signed pieces from Van Cleef & Arpels, David Webb, Bulgari, Tiffany, and others. Nicki Minaj and Rihanna have worn some of her collection. She also sells directly from her Instagram account. The business, she said, is all “about seeing things that others might not see and bring them into their wardrobe and their lives.”

On meeting a client, Ms. Heller said, she can tell within moments — “10 seconds” — what will suit the woman. “Everyone is different, so I find the best for each person,” she said. “I especially love big bold pieces from the ’60s, ’70s and ’80s, which are relevant now, and work with the fashion trends. They’re always so chic and fabulous.”

Ms. Heller grew up surrounded with jewelry, watching her grandmother get dressed in magnificent pieces and traveling to Nepal, India and several African countries with her family. “My father always loved going to flea markets,” she said. “Wherever we were in the world, the first stop we’d make would be the market.” She did not study jewelry formally but was the watches and jewelry editor at Esquire magazine from 1996 to 2000.

As for the hurdles of being a woman working in the jewelry industry, she said she experienced them more “as a single divorced woman, in general, running a business and raising my two children.”

“Finding the right balance — there likely isn’t one,” she added.

And her advice to young women wanting to succeed in the jewelry industry would be the same thing she said she had told her 19-year-old daughter: “Do what you’re passionate about and you’ll be successful. And stick with it.”