An X-ray monolithic 4-block interference system has been developed and manufactured, in which the first 3 blocks are thin and form a 3- block Laue interferometer with disrupted geometry, and the 4th additional block is thick and is in the reflection position. It is shown that fine structures of interference patterns registered from 3-block interferometers with thin blocks and distorted geometry are observed in cases where an additional 4th thick block is used. The calculations show that when the ideal geometry of a 3-block interferometer is violated, an interference pattern is formed in the form of families of parallel stripes (lines) on the recording plate lying perpendicular to the incident beam. The coordinates of the interference stripes maxima, their periods, as well as the coefficient of a linear enlargement in the presence and absence of the 4th thick block, are calculated. It has been experimentally proven that a thick block does not introduce new information into the interference pattern, but will only enlarge its dimensions in the scattering plane. The limits for reducing the period of interference stripes and their complete disappearance are determined depending on the size of violations from the ideal geometry of a 3-block interferometer.