FIELD: gem treatment. SUBSTANCE: method of coloring natural beryl crystals and articles (jeweler's insertions) to improve their color (simulation of emerald) involves irradiation of natural beryl crystals with ionizing radiation and heat treatment and is distinguished with that thermally treated crystals are submitted to a secondary irradiation, the both irradiation steps being effected with 6-8 MeV electron beam at fluency 10 15-2,5•1016 electrons per 1 sq.cm, whereas heat treatment is carried out via slow heating and cooling (2-2.5 deg./h) and exposure to 160-170 C for 1-2 h. EFFECT: improved quality of color.