ИСТИНА

The peculiarities of diamond crystal morphology from the five kimberlite pipes of Arkhangelsky kimberlite province were investigated by optic and microprobe analyses methods. It was distinguished the main crystalomorphological types of a diamond.The long and difficult kimberlite magma evolution accompanied by modification of P-T and redox conditions was traced on the diamond crystal morphology. It was established, that the qualitative and the quantitative distribution of different diamond crystales are specified to each kimberlite field and pipe. The changing of P-T conditions during the diamond growth end postcrystalline dissolution of diamond crystals may have as a result the differences in diamond contents of kimberlite pipes and it must be take into account during prospecting and explorative works.