The article compares the deformation behavior of the minerals of biological and geological genesis under compression and tension. Human tooth enamel, hen’s eggshell (samples compacted from powder of hen’s eggshell), granite, serpentinite, jasper and plasma spraying alumina are taken as the model materials. It is shown that the deformation behavior of both biominerals and rocks in a macroscopic scale is determined by the level of stretching stresses in the load application scheme and changes from brittle under diametral compression to viscoelastic under compression. On a microscopic scale, the behavior of model materials was certi ed as a viscoelastic for all loading schemes.