Genetic crystallography of hexagonal solid solutions of osmium, ruthenium and iridium as an indicator of the conditions of their formation

A different-scaled periodic edge fragmentation of {1010} and {1011} surface s is a particular crystal morphological feature of the individuals of hexag onal solid solutions of osmium, ruthenium, and iridium from the placer occu rrences of the ruthenium-iridium-osmium mineralogical-geochemical type rela ted to the massifs of Alpine-type ultramafites. The study of the reasons of the manifestation of this morphological phenomenon allowed us to suggest a series of concepts on the structural state and different aspects of the cr ystal and morphological genesis. The individuals of the hexagonal solid sol utions of osmium, ruthenium, and iridium represent the deformation-recrysta llized textures and occupy single crystals and their aggregates. The morpho logical manifestation of the deformation influence on the idiomorphic indiv iduals is expressed in a distortion of the angular metrics of their crystal line polyhedra. The edge fragmentation of the {1010} and {1011} surfaces co rresponds geometrically to the structure of the fault bands of the prismati c slipping and manifests itself at a subsequent solution of the individuals . A reconstructed sequence of the factors at the post-growth stage of the c rystal genesis is the high-temperature plastic deformations, partial soluti on, and recrystallization. The semiquantitative evaluation of the temperatu re crystallization range 750-900 degrees C allows one to assign the deforma tion transformations of the individuals of hexagonal solid solutions of osm ium, ruthenium, and iridium to mantle as well as to crustal transformation levels of the peridotite basement of ophiolites. Typomorphic features of th e internal structure, micro- and macro-morphology of the crystals of the so lid solutions of osmium, ruthenium and iridium allow one to state their ont ogenesis and to consider the features as additional criteria for the genesi s of ore deposits.