Material · lithic
Edwards chert
North America — Great Plains
Edwards chert is the high-quality Cretaceous chert of the Edwards Plateau of Central Texas, used from Clovis times through the Historic period and traded onto the Southern Plains. It fluoresces under ultraviolet light, which helps identification. Nearly all Central Texas points are made of it.
| Kind | lithic |
|---|---|
| Regions | North America — Great Plains |
Sources
The Edwards limestone crops out across the Edwards Plateau and the Balcones Escarpment from Austin and San Antonio west toward the Pecos, with nodules in the limestone and abundant cobbles in stream gravels. Georgetown and Fort Hood have well-known outcrops.
Identification
Edwards chert is grey to blue-grey, sometimes tan or brown, fine-grained with a slightly waxy lustre, and many varieties fluoresce yellow-orange under long-wave ultraviolet light. Weathering produces a white to tan patina. Fossil inclusions are uncommon.
Substitutes and fakes
Texas is a centre of modern knapping, and Edwards chert points are made in quantity and aged by patination chemicals; genuine pieces show a natural patina that penetrates rather than coats. Fluorescence does not distinguish old from new.
Cite this article
Stratum Study. "Edwards chert" (Material). Stratum Study pack 2026.09, as of 2026-09-21. https://stratum.black/study/materials/edwards-chert. Accessed 2026-09-21.
@misc{stratum-edwards-chert,
title = {Edwards chert},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/materials/edwards-chert}},
year = {2026},
note = {Material article, Stratum Study pack 2026.09, as of 2026-09-21; sources: stratum. Accessed 2026-09-21.}
} Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.