sedimentary

Banded Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (SiO2)

Hardness: 7 on Mohs scale; Color: reddish-purple/brown with fine greyish-white bands; Luster: dull to waxy; Structure: microcrystalline/cryptocrystalline aggregate; Fracture: conchoidal (shell-like fracture essential for flintknapping).

Hardness: 7 on Mohs scale
Color: reddish-purple/brown with fine greyish-white bands
Luster: dull to waxy

Identified July 25, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed as microcrystalline quartz precipitates in marine sedimentary environments, often forming nodules or layers in limestone or chalk beds. This specimen has been shaped by human flintknapping (knapping/pressure flaking).

Uses & applications

Historically crafted by Indigenous cultures for hunting projectile points (arrowheads or spear points) and cutting tools. Today, it holds historical, archaeological, and collector value.

Geological facts

Chert and flint were crucial resources for ancient humans globally because they fracture predictable conchoidal edges as sharp as modern surgical steel when struck with stone or antler tools.

Field identification & locations

Identified by notched base (stem/notches), distinctive triangular projectile shape, edge flaking scars, and conchoidal fractures along banded silica rock (chert/jasper). Found in ancient camp sites, riverbeds, and cultivated fields.

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