sedimentary

Chert (Arrowheads)

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 Mohs; Color: Brown, tan, reddish-orange; Luster: Waxy to vitreous; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 6
Color: Brown, tan, reddish-orange
Luster: Waxy to vitreous

Identified July 6, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Brown, tan, reddish-orange; Luster: Waxy to vitreous; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the accumulation of silica-rich organic remains or chemical precipitation in sedimentary basins. These specific pieces are anthropogenic artifacts (lithic projectiles) carved from raw chert nodules.

Uses & applications

Historically used for tools and weapons due to sharp edges; currently valued as archaeological artifacts and collectibles.

Geological facts

Chert and flint were the primary materials for stone tool technology for millions of years because of their predictable conchoidal fracturing and extreme sharpness.

Field identification & locations

Identify by the 'flake' scars from knapping (shaping process) and the shell-like (conchoidal) curves where the stone was struck. Commonly found in riverbeds or prehistoric site areas.