Mass precipitation of isomorphic-mixed crystals investigated on the example of the series K(Cl,Br) and (Pb,Ba)(NO3)2 by means of X-ray diffractometry as well as (Co,Ni)(NH4)2(SO4)•6H2O and K(Al,Cr)(SO4)2•12H2O by means of microprobe analyses and X-ray fluorescence, is specified by a bimodal distribution of crystals in sizes and a correlation between sizes and compositions. Relations of characteristics of spontaneous crystals and surface nuclei on seeds were revealed. These phenomena are caused by a microheterogeneity of the segregated solution. They extend the supposed general picture of the ensemble component selection and forming inhomogeneity of mixed crystals.
Key words: mixed crystal formation, mass precipitation, distribution in sizes, distribution in compositions, crystallization mechanism, solution segregation