sedimentary

Chert (Arrowhead)

Chert (SiO2)

Hardness: 6.5-7. Color: Grey to brownish-grey. Luster: Waxy to dull. Crystal structure: Cryptocrystalline. Cleavage: None (conchoidal fracture). Specific gravity: 2.6.

Hardness: 6
Color: Grey to brownish-grey
Luster: Waxy to dull

Identified May 28, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7. Color: Grey to brownish-grey. Luster: Waxy to dull. Crystal structure: Cryptocrystalline. Cleavage: None (conchoidal fracture). Specific gravity: 2.6.

Formation & geological history

Formed as microcrystalline quartz aggregates in sedimentary environments, often replacing carbonate material. This specimen has been anthropogenically worked through pressure flaking.

Uses & applications

Historically used for projectile points, scrapers, and blades. Currently of high archaeological and collector value.

Geological facts

This specimen is a lithic artifact (arrowhead or projectile point). Chert was the primary material for prehistoric tools due to its predictable conchoidal fracturing and razor-sharp edges.

Field identification & locations

Identify by the systematic flake scars and serrated edges. Found in areas with limestone outcroppings or historical human settlements. Collectors should note provenance (find location) for ethical/legal reasons.