X-ray diffraction is a widely used nondestructive method of studying carbon materials. It is employed to study the phase composition of samples, to analyze the qualitative and quantitative composition of specific phases, and to assess the structural characteristics of crystalline carbon materials. In the present work, we calculate the basic structural parameters of graphite after various treatments. The crystalline structure of structure is most commonly characterized by the interplane distance d00l, the dimensions of the structural components La and Lc, and the degree of order. The nonuniformity of the phase compositions is described by comparing data from the primary crystallographic reflexes of the (00l) series, corresponding to the basic plane of graphite. The (002), (004), and (006) reflexes represent the superposition of components characterizing individual structural phases of the samples, with specific interplane distances. By resolution of the reflexes into structural components, an additional characteristic of the sample may be derived: the ratio of the phases. On that basis, the crystalline structure of samples with similar overall structural characteristics may be more accurately characterized. © 2017, Allerton Press, Inc.