By Theba Szile | Updated Mar 24, 2022
Flint knapping—also known as knapping—is the art of shaping stones that fracture conchoidally (convex breakage) by striking them with harder tools. In Missouri, knappers traditionally rely on two main varieties of chert: Mozarkite, the state’s official stone, and Burlington Chert. Other cherts and the metamorphic quartzite also appear in the region.
Mozarkite, found in western Missouri’s Ozark foothills, is a hard, multi‑colored chert composed primarily of micro‑crystalline quartz (SiO₂) and often contains chalcedony. Its distinctive hues—ranging from brown, gray, and purple to green, red, and pink—make it a favorite for both its aesthetic appeal and its ability to polish to a high sheen. According to the Missouri Geological Survey, Mozarkite is prized by modern knappers for its predictable conchoidal fracture.
Burlington Chert typically appears pink, white, or light brown and breaks easily, though the fracture pattern can be irregular, posing a challenge for contemporary knappers. Archaeological evidence from the Missouri Mineral Society shows that prehistoric peoples crafted tools from this material, indicating its long‑standing utility.
Because chert forms from carbonate sedimentary rocks such as dolomite and limestone, Missouri’s landscape is dotted with knappable varieties. Chemical variations and distinct formation processes give rise to a spectrum of colors and patterns, each with unique flaking characteristics. Geologists and hobbyists often assign specific names to cherts that display striking or unusual traits.
Quartzite is a metamorphic stone produced from sandstone under high pressure. While some prehistoric cultures knapped quartzite, modern flint knappers rarely use it due to its difficulty in producing clean, conchoidal fractures.
