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Supplier Spotlight: K. Rosengart

For Karen Rosengart, founder of K. Rosengart, the diamond business is more than a profession—it’s in her blood.

“My father spent his life as a diamond setter, and I was always excited to see the beautiful pieces he made,” says Karen. “I attended the Art Institute of Chicago, and while in school, I was lucky enough to study in London, learning how to design jewelry.”

After graduation, Karen spent some special time at the bench with her father, learning the art of diamond setting. She quickly realized that she wanted to do more in the jewelry business and landed a job at Tiffany & Co. in the buying office.

Karen recalls, “I had an incredible time working there and learned so much. The knowledge I gained at Tiffany catapulted me into specializing in better goods, and in 1996, I opened my own diamond business, K. Rosengart.”

In May 2023, K. Rosengart became a subsidiary of Niru Group. This strategic partnership has provided a multitude of benefits for K. Rosengart and their clients.

“As a subsidiary, I now have the benefit of using Niru’s expertise and technology, freeing me up to offer even more personal service and individual client interaction,” explains Karen. “Niru has allowed me to expand my operation, and using their global organization and infrastructure, I can now provide my clients with an extensive assortment of loose diamonds and diamond jewelry while increasing my ability to offer even more competitive pricing.

“Niru positively impacts people’s lives worldwide and supports the ethical sourcing and the natural integrity of the diamonds they supply. Niru’s reliability and high ethical standards made in a perfect fit for K. Rosengart.”

K. Rosengart became members of the American Gem Society (AGS) in 2018 and maintains their membership as it helps boost consumer confidence in the diamond industry and provides access to educational resources that help companies stay updated with best practices.

Karen explains, “Significantly, AGS supports retailers by offering networking opportunities that can lead to new business relationships, and, as a registered supplier, these opportunities are invaluable. More importantly, AGS’s core values of ethical sourcing and supply integrity naturally fit with K. Rosengart, creating a perfect synergy of business and integrity.”

To learn more about K. Rosengart, visit