The major component and phase compositions of the -32+20 µm ferrosphere fraction, extracted from high-calcium fly ashes, and the compositions of individual globules of different morphological type were studied. It was found that the main phases of the fraction are (1) ferrospinel (31 wt.%) with the lattice parameter close to stoichiometric magnetite parameters, (2) hematite (31 wt.%) with lattice parameters smaller than the stoichiometric hematite parameters and (3) X-ray amorphous phase with unidentified crystalline phases (37 wt.%). According to the SEM-EDS data on powders and polished sections, it was shown that the base types of individual globules are block, skeletal-dendritic and plate types. They show the same surface and bulk crystallization for iron oxide phases and the CaO = f (Fe₂O₃) dependence is described by linear regression equations with high correlation coefficients. The differences of composition for the three main types of globules, were identified.