sedimentary

Chert (Flint Arrowhead)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Dark gray to black. Luster: Waxy to dull. Fracture: Distinctive conchoidal fracture with sharp edges. Structure: Microcrystalline quartz.

Hardness: 7 on Mohs scale
Color: Dark gray to black
Luster: Waxy to dull

Identified July 25, 2026More sedimentary →

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Physical properties

Hardness: 7 on Mohs scale. Color: Dark gray to black. Luster: Waxy to dull. Fracture: Distinctive conchoidal fracture with sharp edges. Structure: Microcrystalline quartz.

Formation & geological history

Formed through biochemical or chemical precipitation of silica in deep-marine or limestone environments. This specimen was knapped by human hands into a point.

Uses & applications

Historically used for tools, weapons, and fire-starting. Modern uses include jewelry, decorative wire-wrapped pendants, and lapidary collections.

Geological facts

Chert and flint break with extremely sharp, razor-thin conchoidal edges, which made them the premier materials for knapping ancient tools, arrowheads, and spear points.

Field identification & locations

Look for microcrystalline quartz texture, hardness capable of scratching glass, and scalloped conchoidal knapping flakes on knapped points. Found globally in limestone formations.