sedimentary

Chert (Arrowhead Fragment)

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale); Color: Dark grey to black; Luster: Dull to waxy; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture).

Hardness: 7 (Mohs scale)
Color: Dark grey to black
Luster: Dull to waxy

Identified July 13, 2026More sedimentary →

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Physical properties

Hardness: 7 (Mohs scale); Color: Dark grey to black; Luster: Dull to waxy; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture).

Formation & geological history

Formed through the accumulation of silica-rich organic remains or chemical precipitation in sedimentary environments. Chert can form as nodules in limestone or as distinct bedded deposits.

Uses & applications

Historically used for stone tools like arrowheads and scrapers due to its conchoidal fracture and sharp edges. Today used as a collector specimen or in industrial grinding media.

Geological facts

This specimen appears to be a lithic flake or a fragment of a projectile point (arrowhead), showing evidence of intentional 'knapping' or flaking by humans.

Field identification & locations

Identify by its waxy luster and shell-like (conchoidal) fracture patterns. Frequently found in stream beds or limestone outcrops. Check local laws before collecting artifacts.