Determined that, morphological differences of Iceland spar crystals on the «Razlom» deposit are due to the nature of their nucleation in the cavities of the system: in the central part of field the crystals, twinned by law 6'/m'mm', formed at growing individuals parallel-columnar aggregates; in the edge of dikes, the twins by law m'mm' («butterfly») were nucleated in the deformed and twinned on (0112) and (0221) grains of early calcite generation of introduced solutions in the cavity of tectonic zones. Large size and high degree of homogeneity of Iceland spar in the field is due to the stability of tectonic conditions located in the crystallization zone of stepinflection of complex (three-member) dolerite dikes, where a right-hand shift, which is supervising field, during the crystallization of calcite did not result in a significant disruption of the integrity of the system of saline cavities.

Keywords

Iceland spar, calcite, «Razlom» deposit, twins, dike.