Gemological Science International (GSI), one of the world’s largest gemological organizations, has identified undisclosed lab-grown diamonds in jewelry set with natural brown diamonds. The discovery comes at a critical time, as the global jewelry trade increasingly promotes off-color natural diamonds, such as brown and champagne hues, as unique, fashionable, and affordable alternatives to traditional colorless stones.

Using advanced instrumentation, including Fourier Transform Infrared Spectroscopy (FTIR), DiamondView imaging, and Raman spectroscopy with liquid nitrogen cooling, GSI gemologists confirmed that several jewelry items contained lab-grown diamonds mixed alongside natural brown stones. The detected colors ranged from near colorless with faint brown modifiers to fancy dark brown.

This finding builds on GSI’s earlier research into colored lab-grown diamonds, which demonstrated that synthetics can mimic a broad spectrum of natural hues. Together, these results highlight the importance of rigorous screening protocols and transparent disclosure practices to protect both industry stakeholders and consumers.

“As the industry embraces natural brown diamonds, it is essential to safeguard their integrity in the marketplace,” said Debbie Azar, President and Co-Founder of GSI. “Our mission is to ensure consumer confidence by applying advanced science to protect retailers, manufacturers, and the trade — and to support the industry’s efforts to promote natural off-color diamonds with trust and transparency.”