Ichetyu diamonds: constitution, surface film micromineralization, genesis

Diamonds from the Ichetyu deposit of disputable genesis have been studied using X-ray diffraction analysis,scanning electron microscopy, cathode-, photo- and X-ray luminescence; spectroscopy of Raman scatteringand IR absorption, LA-ICP-MS, isotope mass spectrometry. The crystal morphology of diamonds has beenanalyzed, the parameters of the forms of their mantle dissolution, the degree and nature of plastic and impactdeformations have been determined. Features of the internal structure, luminescent-spectroscopic propertieswere revealed. The bulk concentration of structural nitrogen, the degree of aggregation of point nitrogen defects, and the temperature of mantle annealing are estimated. The composition of microelements and carbonisotopy were determined. The mineral-phase composition of films on the surface of diamonds has been studied. A conclusion was made about the tuffizite-fluidisite genetic type of the Ichetyu deposit.