Conchoidal fracture

Conchoidal fracture is a type of breakage that occurs in certain materials, most notably in glass, quartz, and some other minerals. It is characterized by smooth, curved surfaces that resemble the shape of a shell or the curves of a conch. This type of fracture does not follow any predetermined planes of weakness (such as cleavage or grain boundaries) and instead propagates in a way that creates sharp, glassy edges.