Knapping

Knapping (/ˈnæpɪŋ/ NAP-ing) is the shaping of flint, chert, obsidian, or other conchoidal fracturing stone through the process of lithic reduction to manufacture stone tools, strikers for flintlock firearms, or to produce flat-faced stones for building or facing walls, and flushwork decoration. The term “knap”(1500s) was originally onomatopoeic and meant “strike with a sharp sound” (with the k- pronounced) and later shifted to mean “to shape or work by sharp strikes”. Modern usage is more specific, referring almost exclusively to the free hand percussion process pictured. It is distinguished from the more general verb "chip" (to break up into small pieces, or unintentionally break off a piece of something) and is different from "carve" (removing only part of a face), and "cleave" (breaking along a natural plane).