Conchoidalen

Conchoidalen is a term used in geology and materials science to describe a specific type of fracture surface observed in brittle materials, particularly amorphous solids like glass and many minerals. This fracture pattern is characterized by its smooth, curved, and shell-like appearance, resembling the interior of a seashell. The characteristic features of conchoidal fracture include concentric, parabolic, or circular ridges, often referred to as arrest lines or hackles, which emanate from a central point of origin. The absence of cleavage planes, which are characteristic of crystalline materials, is a key factor leading to conchoidal fracture. When a brittle material under stress breaks without following a specific crystalline structure, the fracture propagates outwards, creating these curved surfaces. Examples of materials that commonly exhibit conchoidal fracture include obsidian, flint, chert, and quartz. The study of conchoidal fracture surfaces can provide valuable information about the stress conditions and the fracture mechanics of the material. It is a phenomenon observed both in natural geological formations and in manufactured materials.