fossil
Chert (Arrowhead Point)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Hardness: 6.5-7 Mohs; Color: Tan, beige, or brown with mottling; Luster: Dull to waxy; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture).
- Hardness
- 6
- Color
- Tan, beige, or brown with mottling
- Luster
- Dull to waxy
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Physical properties
Hardness: 6.5-7 Mohs; Color: Tan, beige, or brown with mottling; Luster: Dull to waxy; Structure: Cryptocrystalline; Cleavage: None (conchoidal fracture).
Formation & geological history
Formed through the accumulation of silica-rich organic remains or chemical precipitation in sedimentary environments. As an artifact, it was knapped by humans during the Stone Age or later periods.
Uses & applications
Historically used for tools and weaponry; currently valued as an archaeological artifact and for hobbyist collecting.
Geological facts
Chert is favored for stone tools because it fractures predictably in a process called conchoidal fracture, creating very sharp edges.
Field identification & locations
Identified by its triangular or leaf-like worked shape and characteristic flake scars. Commonly found in areas with high limestone concentrations or at known archaeological sites.
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