I. V. Zhernovskii*, and A. G. Mochalov**
* North-East Complex Scientific Research Institute, Far East Division, Russian Academy of Sciences,
ul. Portovaya 16, Magadan, 685010 Russia
** Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry (IGEM),
Russian Academy of Sciences, Staromonetnyi per. 35, Moscow, 109017 Russia
Received April 8, 1999
Abstract—A different-scaled periodic edge fragmentation of {1010} and {1011} surfaces is a particular crys-
tal morphological feature of the individuals of hexagonal solid solutions of osmium, ruthenium, and iridium
from the placer occurrences of the ruthenium–iridium–osmium mineralogical-geochemical type related to the
massifs of Alpine-type ultramafites. The study of the reasons of the manifestation of this morphological phe-
nomenon allowed us to suggest a series of concepts on the structural state and different aspects of the crystal
and morphological genesis. The individuals of the hexagonal solid solutions of osmium, ruthenium, and iridium
represent the deformation-recrystallized textures and occupy single crystals and their aggregates. The morpho-
logical manifestation of the deformation influence on the idiomorphic individuals is expressed in a distortion
of the angular metrics of their crystalline polyhedra. The edge fragmentation of the {1010} and {1011} surfaces
corresponds geometrically to the structure of the fault bands of the prismatic slipping and manifests itself at a
subsequent solution of the individuals. A reconstructed sequence of the factors at the post-growth stage of the
crystal genesis is the high-temperature plastic deformations, partial solution, and recrystallization. The semi-
quantitative evaluation of the temperature crystallization range 750–900°C allows one to assign the deformation
transformations of the individuals of hexagonal solid solutions of osmium, ruthenium, and iridium to mantle as
well as to crustal transformation levels of the peridotite basement of ophiolites. Typomorphic features of the
internal structure, micro- and macro-morphology of the crystals of the solid solutions of osmium, ruthenium
and iridium allow one to state their ontogenesis and to consider the features as additional criteria for the genesis
of ore deposits.
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