To shape a hard, brittle material (such as flint, obsidian, chert etc.) by breaking away sections or flakes, often forming a sharp edge or point. Distinguished from "carve" because each fracture goes across one entire face or facet, and from "cleave" because breaking (knapping) vitreous, brittle homogeneous (i.e., not crystalline) materials inevitably results in curved, conchoidal fractures
To shape a hard, brittle material (usually flint or obsidian) by breaking away sections, often forming a sharp edge or point. Distinguished from "carve" by the fact that each fracture goes through the entire work piece, and from "cleave" by curved or conchoid fractures (due to the work piece not being a single crystal)