Named stone
Georgetown chert
Also called Georgetown flint
A kind of chert (and flint)
Georgetown chertChert (and flint)Texas & SouthwestDescription
Georgetown flint is a gray, glassy chert from the eastern edge of the Edwards Plateau, in Williamson County and probably southern Bell County. Its best form is a steel-gray, translucent, brittle stone that Texas Beyond History says rivals any natural siliceous stone in North America for flaking. It occurs as ledge flint in bands about 4 to 20 cm thick, as flat cobbles 4 to 10 cm thick, and as rounded nodules up to about 30 cm. Prehistoric people clearly sought it out, taking it from outcrops and downstream gravel bars. Large, very thin bifaces of it turn up hundreds of miles away, including Gahagan knives placed in Early Caddo graves at the George C. Davis site, and it is known from Clovis caches. A look-alike stone occurs in Hays County.
How to identify it
- Colour
- Several shades of gray; four varieties ('flavors') in one quarry, the best a steel gray.
- Texture
- Glassy and brittle; flaking quality is rated among the best in North America.
- Luster
- Glassy and translucent in the best material.
- Heat treatment
- Some Georgetown flint improves with heat treatment, but the best material is ideal for knapping as it is.
Geology
A localized chert from the Edwards Limestone formation, found in place in Williamson County and probably southern Bell County, along the eastern fringe of the Edwards Plateau (Balcones Escarpment). Chert is also carried into downstream gravel bars. A very similar chert in Hays County limestone quarries is regarded by knappers as a close relative.
Where it comes from
Texas & Southwest
States
Quarries and outcrops
- Texas Crushed Stone quarry, south of Georgetown, Williamson County (modern knapper source since the early 1970s)
- Williamson County and southern Bell County outcrops
- Downstream gravel bars along the Balcones Escarpment
- Hays County quarries (a very similar chert)
Used by
- Clovis (caches dating to about 11,000 B.C. or earlier)
- Early Caddo (about 1,100 years ago): Gahagan knives as grave offerings at the George C. Davis site, Cherokee County
- Used through all prehistoric periods
Look-alikes
Stones that are easy to confuse with Georgetown chert.
- Hays County 'close cousin' chert (found in limestone quarries there)
Sources
- Texas Beyond History (University of Texas at Austin, Texas Archeological Research Laboratory). Georgetown Flint. Plateaus and Canyonlands section.texasbeyondhistory.net (opens in a new tab)