Electron Paramagnetic Resonance: An Aid in Solving Topical Problems of Diamonds

We have developed a nondestructive method for identification of diamonds of various origins, which is based on analysis of the EPR data on impurities, defects, ferromagnetic inclusions, resistance of the defect-and-impurity states of diamonds to external actions as well as on peculiarities of distribution, interaction, relaxation and cross-relaxation of paramagnetic centers. The suggested method allows a practically complete identification of the diamond sample, i.e., it answers the following questions: is the crystal a natural or a synthetic diamond? Has it formed under static or dynamic conditions? What is the degree of the development and activity of the sample surface? What ferromagnetic materials are contained in the growth system (hence, a possible manufacturer)? Has been the test sample subjected to an additional external action? etc. We have considered some topical problems, in solving of which the developed method of identification proved to be efficient (at: synthesis of diamond, exploration and development of new deposits, customs examination, ascertainment of the authenticity of the museum displays, sorting of diamonds, etc.).