sedimentary

Chert (Arrowhead)

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 Mohs; Color: Tan to reddish-brown; Luster: Waxy to vitreous; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Translucent edges.

Hardness: 6
Color: Tan to reddish-brown
Luster: Waxy to vitreous

Identified July 5, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Tan to reddish-brown; Luster: Waxy to vitreous; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Translucent edges.

Formation & geological history

Formed through the accumulation of silica-rich microfossils or precipitation from silica-rich fluids in sedimentary basins. This specimen has been anthropogenically modified through flint knapping.

Uses & applications

Historically used for tools and weapons; currently valued as an archaeological artifact or for lithic studies and private collections.

Geological facts

Chert is favored for stone tools because its conchoidal fracture creates edges sharper than a steel scalpel. This specific piece is a projectile point, possibly from the Archaic or Woodland period depending on the region found.

Field identification & locations

Identified by the distinct 'flakes' or 'scars' from percussion and pressure flaking. Often found in proximity to ancient water sources or riverbanks where raw material was abundant.