Аннотация:In the present work, the crystal growth experiments were carried out by cooling paraffin melt in the temperature range of 55-25oC using crystalline (quartz) and non-crystalline (glass) substrates . The grown crystals were studied by electron and optical microscopies, and also by X-ray diffraction method. It was identified both hexagonal and orthorhombic crystals. Hexagonal and orthorhombic forms of normal paraffins crystallize at the cooling rates of 25.5, 10 and 4oC/h in the above temperature range, and dimensions of the plate-like crystals increase in about 1.5-2 times with decreasing cooling rates. Final crystalline solids contain about 85 wt.% orthorhombic paraffin crystals. Hexagonal paraffins were partly presented by dendrites. Structural characteristics and type of the grown paraffin crystals were determined from X-ray diffraction patterns. Size and morphology of these crystals depend on the crystallographic orientation of quartz substrates in the temperature interval of 50-25oC.