sedimentary
Chert (Arrowhead/Scraper Preform)
Silicon dioxide (SiO2)
Hardness: 7 (Mohs scale), Color: tan, grey, buff, and cream with waxy to dull luster, Conchoidal fracture, Kryptocrystalline structure
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Physical properties
Hardness: 7 (Mohs scale), Color: tan, grey, buff, and cream with waxy to dull luster, Conchoidal fracture, Kryptocrystalline structure
Formation & geological history
Formed by the precipitation of silica from seawater or the replacement of limestone by silica-rich fluids. This specific specimen has been worked by humans (knapping) into a tool preform.
Uses & applications
Archaeological artifact (scraper or pre-form for a projectile point). Historically used for tools due to sharp edges; currently valued by collectors of lithic artifacts.
Geological facts
The specimen shows clear evidence of percussion flaking, a process where flakes are struck off a core to create a sharp edge. The waxy texture suggests the specimen might have been heat-treated by ancient makers to improve flaking qualities.
Field identification & locations
Identify by looking for 'bulb of percussion' and conchoidal flake scars that do not occur naturally. Found in areas with high limestone concentrations or along riverbanks where ancient camps were located.
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