An EBSD study of olivine inclusions in Siberian diamonds: Evidence for syngenetic growth?

Crystallographic relations between four diamonds from the Yubileinaya pipe (Yakutia) and inclusions of eight olivine crystals in them are first studied by the EBSD method. Crystallographic coincidence between the olivine and diamond has been revealed in 15 samples, though we failed to make an unambiguous conclusion about the sequence of the mineral crystallization. It is confirmed that the new approach is promising for elucidation of the regularities of the mutual orientation of diamond and inclusion. However, more samples are required to establish whether the olivines formed earlier than the diamonds (protogenetic inclusions) or synchronously with them (syngenetic inclusions).