sedimentary
Chert (Arrowhead/Projectile Point)
Chert (Cryptocrystalline Quartz, SiO2)
Hardness: 7 (Mohs scale), Color: Brownish-grey to smoky, Luster: Waxy to dull, Structure: Cryptocrystalline, cleavage: None (conchoidal fracture), Specific Gravity: 2.65
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Physical properties
Hardness: 7 (Mohs scale), Color: Brownish-grey to smoky, Luster: Waxy to dull, 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 environments. This specific specimen has been anthropogenically worked via knapping into a projectile point shape.
Uses & applications
Historically used for tools and weapons; currently valued as an archaeological artifact and for hobbyist flintknapping.
Geological facts
Chert has been used by humans for millions of years due to its predictable conchoidal fracture, allowing for the creation of razor-sharp edges. It is often referred to as 'flint' in archaeological contexts.
Field identification & locations
Identify by its waxy texture, hardness (will scratch glass), and characteristic flake scars from tool making. Often found in riverbeds or limestone outcroppings.
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