Micro-WorldGems & Gemology, Summer 2026, Vol. 62, No. 2

Colorful Mosaic Pattern in Heated Orange Sapphire

E. Billie Hughes

When viewing this inclusion scene (see above), one might wonder whether it represents a gemstone inclusion at all. This image has invoked comparisons 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 is composed of tiny thin-film decrepitation inclusions inside a beryllium-diffused orange sapphire. While this inclusion scene is not itself diagnostic of diffusion, it is likely the result of high-temperature heat treatment.

E. Billie Hughes is a gemologist and cofounder of Lotus Gemology in Bangkok.

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