Americium-241 (7.35)
At least one U.S. patent employs the use of americium-241 to irradiate diamonds, causing green color changes by having direct contact with the radioactive component in the early 1970s and later. The synthetic radioactive element Americium-241 decays by releasing gamma rays and alpha particles. A cut and polished diamond is exposed in prolonged close proximity with radioactive particles through the procedure. The process left the diamonds somewhat weakly radioactive and generated surface contaminants and radiation stains which were visible under magnification.
Surface Stains: The diamond's surface reveals distinctive green, inert, superficial radiation stains that contrast with its inherent blue fluorescence when viewed under a microscope.
Safety and Identification: These diamonds can be identified with a Geiger counter due to their mild radioactivity.
Current Methods: Since radioactive salt treatment can produce extremely radioactivity in diamonds, it is rarely utilized anymore. Instead, low-energy electron beams are commonly employed in modern artificial irradiation.
