sedimentary
Chert Arrowhead
Cryptocrystalline microcrystalline Quartz (SiO2)
Hardness: 7; Color: Grayish-brown; Luster: Waxy to dull; Crystal structure: Trigonal (microscopic); Cleavage: None (conchoidal fracture); Specific gravity: 2.65
- Hardness
- 7
- Color
- Grayish-brown
- Luster
- Waxy to dull
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Physical properties
Hardness: 7; Color: Grayish-brown; Luster: Waxy to dull; Crystal structure: Trigonal (microscopic); Cleavage: None (conchoidal fracture); Specific gravity: 2.65
Formation & geological history
Formation occurs as nodules or beds in limestone or chalk through chemical precipitation of silica. This specimen has been anthropogenically modified through flint knapping. Age can range from millions of years for the stone to thousands of years for the artifact.
Uses & applications
Historically used for hunting and tools; currently valued as an archaeological artifact and collector's item.
Geological facts
Arrowheads are technically projectile points. Chert was favored by ancient peoples because its conchoidal fracture allows for the creation of extremely sharp, durable edges.
Field identification & locations
Identified by the distinct flaking patterns (scars) from the knapping process and its triangular, notched shape. Commonly found in areas with high limestone concentrations or ancient habitation sites.
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