Luminescence of zircons from highly diamondiferous kimberlites of Yakutia

Abstract

This paper presents the results of studies of X-ray luminescence (XL) of zircons from three highly diamondiferous kimberlite pipes in Yakutia (Russia). Those zircons acquired the typical rounded shape as a result of ancient mechanical abrasion or dissolution. The photoluminescence (PL) color of zircons varies from blue-green to yellow-orange. The PL spectra contain from one to three structureless bands. The color saturation of samples depends on the source and increases in the sequence Mir – Udachnaya – Nyurbinskaya pipes. The system of peaks at 480 and 580 nm, characteristic of rare earth elements, were observed in all X-ray luminescence spectra. The relative intensity of luminescence of the 380 nm band in XL spectrum decreases with increasing color saturation and increases with the lightening of crystals during annealing. The intensity of the 450–650 nm band with a maximum at 540 nm changes slightly during annealing up to 500°C. Zircons are colored under influence of X-ray radiation – at least two types of absorbing defects (color centers) are formed, the concentration of the color centers linearly depends on the irradiation dose. The similarities and differences between zircons from the main industrial kimberlite diamond deposits of Yakutia are shown.