sedimentary

Chert (Arrowhead Artifact)

Microcrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 7; Color: Tan, brown, and grey; Luster: Waxy or dull; Crystal structure: Cryptocrystalline; Conchoidal fracture; Opaque to translucent.

Hardness: 7
Color: Tan, brown, and grey
Luster: Waxy or dull

Identified July 19, 2026More sedimentary →

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Physical properties

Hardness: 7; Color: Tan, brown, and grey; Luster: Waxy or dull; Crystal structure: Cryptocrystalline; Conchoidal fracture; Opaque to translucent.

Formation & geological history

Formed as nodules or beds in sedimentary rocks like limestone or through the replacement of organic tissue (petrifaction). This specimen has been anthropogenically modified through knapping.

Uses & applications

Historically used for stone tools (arrowheads, scrapers, knives) due to its sharp edges; currently valued by archaeologists and artifact collectors.

Geological facts

Chert and flint were among the first materials used by early humans for tools because of their predictable conchoidal fracturing and extreme durability.

Field identification & locations

Identify by its waxy luster, smooth fracture surfaces, and evidence of 'flaking' or 'knapping' edges. Common in areas with limestone or chalk deposits.