Septaria are calcareous clay concretionary nodules with radial compacted cracks predominantly filled with calcite. In the Karachay-Cherkess Republic, the specimens of jewelry and ornamental quality are associated with the Aptian tier of the Lower Cretaceous. Calcite veins are monomineral and have symmetrical structure, due to the simultaneous and similar in rate growth of crystals from opposite walls of cracks. Mineralization was characterized by the lack of metasomatic substitution of the host marl with successive formation of layers of diff erent structures and colors, without their signifi cant recrystallization. Septaria greatly vary in their sizes and are of high decorativeness and positive technological characteristics, and thus are actively used for manufacture of various types of products. Septaria can be collected in large volumes in river valleys without considerable expenses and violating the environment.