GENETIC ASPECTS OF THE DIAMOND MORPHOLOGY

Abstract

The most typical features on the octahedral faces and rhombic dodecahedroidal surfaces of natural diamonds from kimberlites are described. The surface features are classified into three groups by their coexistence on the natural diamonds. It is suggested that the features of one group are genetically related. The experimental data on etching of the diamond crystals indicate a dependence of crystal morphology on the etching conditions. The changing conditions, primarily redox and fluid regimes, lead to the formation of the diamond etch features of three types, which are consistent with the above three groups of surface features on the natural diamond crystals. It is concluded that the surface morphology of the natural stones develops mainly during the natural dissolution. The available statistical data on diamonds from kimberlites of the Yakutian province suggest only two variants of distribution of morphological types, which are related to the abundance of dissolution features or approximately equal abundances of growth and dissolution features.