Methodological Aspects of Diamond Diagnostics for Solving of Geological Interpretation Problems

Abstract

The article reveals the results of the long-term studies for diamond crystals found on the territory of Primorye in placer samples. The crystals’ optical and gemological characteristics, morphology, and the composition of micro inclusions were examined with the microprobe method. Special attention was paid to the study of the photoluminescence spectra of the diamonds, since it is one of the relatively new methods which enables to determine the origin of the diamonds. The rapid development of technologies for the synthetic technical-grade diamonds production has expanded the usage of rough diamonds, including the field of geological exploration. It is widely known that the natural diamonds of technical quality were initially used for making diamond crowns (the end of the XIX century and the beginning of the XX century). Synthetic diamonds are also used to produce crown bits, since the volume of their production is several times higher than the volume of the natural diamonds extraction. The synthetic diamonds properties are similar to those of the natural ones; synthetic diamonds are equal to natural diamonds in abrasive qualities, and the most important thing is that they have a lower processing cost. During the long-term exploitation of drilling crowns, diamond grains may fall out of their seats and be lost. This creates a real risk of natural objects contamination while searching new indigenous diamond deposits. The paper gives an algorithm of research conduction that allows to distinguish between natural and synthetic diamonds, prevent incorrect conclusions and to increase the validity of natural diamond findings in placer deposits.