Figure 35. A wide variation in the penetration depths ofsurface-conformal color layers can be seen in this groupof faceted Be-diffused sapphires (0.51–1.92 ct), immersedin methylene iodide. Photo by Maha Tannous.Figure 36. The vast majority of predominantly red Bediffused samples we examined showed a relativelythin, surface-conformal layer of orange color. The layerin this 5.05 ct stone is somewhat uneven, which suggests that it was recut after treatment. Photomicrograph by Shane F. McClure; immersion, magnified 10×.