FIELD: physical processes establishing presence of impurities in crystals needed for utilization of quality and classification of precious synthetic and natural minerals, such as diamonds. SUBSTANCE: evaluation of concentration of nitrogen defects in diamonds is carried out by value of intensity of re-absorption by no-background component of N3-system in A band of crystal luminescence stimulated by X-rays. Utilization of inherent radiation of crystal in the capacity of sounding optical radiation diminishes requirements to quality of its cutting, it makes measurement low-sensitive to scattering and reflection of light by surface of diamond which substantially limits employment of traditional spectroscopy of optical absorption for these purposes. EFFECT: expanded range of crystals suitable for measurements, high-speed of method. 1 cl, 4 dwg
