What happens when an irradiated diamond is annealed?

• A. Annealing reorganization of color centers to further change the bodycolor.
• B. Annealing eliminates all color centers.
• C. Annealing has no effect on color.
• D. Annealing only affects surface features.

Answer: (A)

Color in irradiated diamonds comes from color centers—defects in the lattice that absorb specific wavelengths of light. Irradiation creates these centers, producing colors such as blue, green, or brown. When you anneal the diamond, you’re supplying heat energy that allows those defects to migrate and interact, reorganizing the color centers into new configurations. This reorganization changes the way light is absorbed, so the bodycolor can become more intense, shift to a different hue, or otherwise alter from its initial irradiated state. It isn’t about erasing color centers or leaving color unchanged, and the effect isn’t limited to the surface—the centers lie inside the lattice and are affected by the heat treatment.