sedimentary

Chert / Flint (Flaked Stone Tool / Projectile Point)

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale. Color: Light gray, weathered patina. Luster: Waxy to dull. Crystal structure: Cryptocrystalline/microcrystalline quartz. Cleavage: None, exhibits conchoidal fracture.

Hardness: 7 on Mohs scale
Color: Light gray, weathered patina
Luster: Waxy to dull

Identified August 3, 2026More sedimentary →

Explore Chert / Flint (Flaked Stone Tool / Projectile Point) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 on Mohs scale. Color: Light gray, weathered patina. Luster: Waxy to dull. Crystal structure: Cryptocrystalline/microcrystalline quartz. Cleavage: None, exhibits conchoidal fracture.

Formation & geological history

Formed via the chemical precipitation of silica in marine environments (such as chalk or limestone deposits) over millions of years. This specific specimen has been intentionally shaped by human knapping.

Uses & applications

Historically used by indigenous peoples and ancient humans for making tools, blades, and projectile points due to its sharp edges when fractured.

Geological facts

Chert and flint were vital materials for early human survival, used extensively for hunting, cutting, and starting fires (when struck against iron pyrite or steel).

Field identification & locations

Found in sedimentary rock formations worldwide, particularly limestone and chalk beds. Look for smooth, conchoidal fracture patterns and evidence of human retouching or percussion flaking along the edges.