Chert

What is chert? Chert is silicon dioxide, chemically the same as quartz or glass, but formed by sedimentary processes. It can be formed in two ways. It can crystallize out of solution into a mineral called chalcedony, or it can be incorporated in animal shells and settle to the bottom when the animals die. Hardness 7, Specific gravity 2.6.

Chert is hard and shiny and comes in many colors

Where is it found geographically? Chert is found primarily in middle Tennessee on the Highland Rim and the counties around the upper Tennessee River.

When was it deposited? Small amounts of chert in all of the limestone layers of. In the early Ordovician, middle Devonian and the early Mississippian Periods, however, large amounts of chert were deposited. These deposits are found in the Ordovician Knox Formation in East Tennessee, the Devonian Camden Chert in West Tennessee, and in the Mississippian Fort Payne and St. Louis Formations in Middle Tennessee.
Quaternary
Tertiary
Cretaceous
Jurassic
Triassic
Permian
Pennsylvanian
Mississippian
Devonian
Silurian
Ordovician
Cambrian
Proterozoic
History of chert use in Tennessee The earliest chert implements found in Tennessee are from the Clovis culture, an early native American culture and probably date from about 10,000 years ago, when humans first came to Tennessee. Chert tools and weapons were used in Tennessee until they were replaced by metal tools and weapons after the coming of Europeans. (Description of flint artifacts found in Tennessee, Pictures of arrowheads found in Tennessee).

In recent years crushed chert is used for road beds.

picture from Tennessee Archaeology Awareness Week poster, September 15-23, 2001. Department of Sociology and Anthropology, MTSU

How is it mined and used? Chert in Tennessee was used by native peoples primarily to make tools and weapons. Because it is the rock itself that is used and only small quantities are needed it doesn't need a complex mining process. Forming tools from chert is a process called knapping. There are a number of pages which illustrate how to do this. (Mike's Arrowhead Page, Sources of flint-knapping materials,