What effect do gamma rays have on saltwater cultured pearls?

Gamma rays interact with the materials in saltwater cultured pearls, particularly affecting the bead nucleus. When subjected to gamma radiation, the nacre (the iridescent layer of the pearl) can undergo changes that result in the darkening of the bead nucleus. This darkening effect occurs because gamma rays can influence the physical and chemical structure of the materials within the pearl, leading to alterations in color intensity and appearance.

This understanding highlights the importance of radiation exposure in the treatment and enhancement of pearls, emphasizing that while gamma rays might be used for other purposes in gemology, their primary effect in this case is the darkening of the bead nucleus rather than enhancing luster, increasing size, or causing a loss of color.