Figure 39. A Be-diffused stone will not always have a complete surface-conformal layer of color, which could causeconfusion with natural color zoning. We had the diffused piece of rough on the left cut into the 1.74 ct stone in thecenter. As can be seen with immersion on the right, the orange diffusion layer was evident only as concentrationsjust under the surface along the edges of the table and one side of the pavilion, and not all the way around the stone.Left and center photos by Maha Tannous; photomicrograph on the right by Shane F. McClure, magnified 10×