sedimentary

Chert (Arrowhead/Projectile Point)

Microcrystalline Quartz (SiO2)

Hardness of 7 on the Mohs scale, typically white to light grey or tan in color, waxy to vitreous luster, cryptocrystalline structure, conchoidal fracture with no cleavage, specific gravity of roughly 2.60 to 2.65.

Identified August 3, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed in marine environments through the chemical precipitation of silica from seawater or the replacement of limestone/chalk by silica-rich solutions during diagenesis. This specific specimen has been hand-worked into a projectile point.

Uses & applications

Historically used by indigenous peoples for tools and weaponry such as arrowheads, spear points, and scrapers. Today, it is highly valued by artifact collectors and enthusiasts.

Geological facts

Chert breaks with a very sharp, predictable conchoidal fracture, making it an ideal material for flintknapping. Light-colored varieties are frequently referred to locally as 'flint' or 'chert'.

Field identification & locations

Identify by its waxy luster, conchoidal edges, and lack of visible crystal grains. Often found in limestone formations or as surface finds in areas with rich archaeological history. Common locations include riverbeds and plowed agricultural fields.

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