Microinclusions in Diamonds of Octahedral Habit from Kimberlites of Shandong Province,Eastern China

摘要

Microinclusions in octahedral diamond crystals from kimberlites of Shandong Province,eastern China,have been studied with analytical scanning electron microscopy.Native iron,tungsten,and lead;Fe-Cr intermetallic compounds;polydymite;ilmenite;halite;and matlockite (PbFCl) have been identified on the crystal surfaces.Microinclusions of native iron and chrome,Fe-Cr intermetallic compounds,pentlandite,Cr-free garnet,calcite,and apatite,as well as a relatively large (100 x 270 mu m) inclusion representing an intergrowth of clinopyroxene,calcite,and apatite,have been revealed on the surfaces of fresh chips of the samples.The deep geological processes that could have resulted in the formation of such unusual mineral assemblages are discussed in the light of new experimental data.