Texture and grain size is of great importance in understanding the mechanical properties of rocks. The aim of this study was to investigate textural and slaking durability characteristics, and correlate them with the gypsum types where the dolines occurred, with particular reference to the texture and crystal size. The investigation comprised two stages: field work and laboratory testing. Initially, rock samples were obtained from various representative karstified and non-karstified locations. Thereafter, mineralogical, physical and slaking durability characteristics of the gypsum samples were determined by means of laboratory testing. After the field and laboratory works, the geological, mineralogical and slaking durability characteristics of the study area gypsum were reviewed and discussed from the point of view of doline formation. Results showed that fine grain sized alabastrine gypsum tends to be karstified and leads to doline formation. This is closely related to the crystal size, texture and attributable to the slaking durability of the gypsum. Consequently, the results demonstrate that the texture, especially crystal size, and effective porosity are important parameters controlling the slake durability of the gypsum and doline formation.