Beryl over , and its dimensions were long and in diameter. The largest cut aquamarine gem is the Dom Pedro aquamarine, now housed in the Smithsonian Institution's National Museum of Natural History. The ancient Romans believed that aquamarine would protect against any dangers while travelling at sea, and that it provided energy and cured laziness. Emerald is green beryl, colored by trace amounts of chromium and sometimes vanadium. Most emeralds are highly included, so their brittleness (resistance to breakage) is classified as generally poor. The modern English word "emerald" comes via Middle English "Emeraude", imported from modern French via Old French
Gemstone irradiation Gemstone irradiation The gemstone irradiation is a process in which a gemstone is artificially irradiated in order to enhance its optical properties. High levels of ionizing radiation can change the atomic structure of the gemstone's crystal lattice, which in turn alters the optical properties within it. As a result, the gemstone's color may be significantly altered or the visibility of its inclusions may be lessened. The process, widely practised in jewelry industry, is done in either a nuclear reactor for neutron bombardment, a particle accelerator for electron bombardment, or a gamma ray facility using the radioactive isotope cobalt-60. Irradiation has