Colorful mosaic-like inclusions in a heated orange sapphire reveal tiny thin-film decrepitation inclusions associated with high-temperature heat treatment.
When viewing this inclusion scene (see below), one might wonder whether it represents a gemstone inclusion at all. The image has been compared to fireworks illuminating a night sky, a mosaic-like stained-glass window, and the plates used in the Ishihara test for color blindness. In reality, the scene consists of tiny thin-film decrepitation inclusions within a beryllium-diffused orange sapphire. Although this inclusion scene is not itself diagnostic of beryllium diffusion, it is likely the result of high-temperature heat treatment.
Thin-film decrepitation inclusions create a colorful mosaic pattern in a beryllium-diffused orange sapphire under diffused fiber-optic lighting. Photo: E. Billie Hughes/Lotus Gemology. Field of view: 1.6 mm.
About the Author
E. Billie Hughes is Co-Founder and Managing Director of Lotus Gemology, where she oversees the company's day-to-day operations while continuing gemological research and laboratory work. After graduating from UCLA, she became a Fellow of the Gemmological Association of Great Britain (FGA). Her research focuses on ruby and sapphire, including low-temperature heat treatment, and she has authored and co-authored articles in leading gemological journals. She has conducted fieldwork at gem deposits around the world, including nearly every major ruby and sapphire locality.
Billie is an internationally recognized educator who has lectured for trade organizations, museums, and luxury jewelry houses, including extensive educational work with Van Cleef & Arpels. She has also served as a judge on Thailand's The Secret Gems television series. An award-winning photographer and photomicrographer, her images have received honors in the Nikon Small World and Gem-A competitions and have appeared in publications including National Geographic and Forbes. She is also the creator of Hyperion, Lotus Gemology's online inclusion database.
Billie developed an interest in gemstones from an early age, accompanying her parents on expeditions to mines and gem-producing regions around the world. That lifelong passion for fieldwork, laboratory research, education, and photography continues to shape her work at Lotus Gemology today.
Notes
First published in Gems & Gemology, 2026, Vol. 62, No. 2, Summer, p. 211.