sedimentary
Chert (Arrowhead Artifact)
Microcrystalline Quartz (SiO2)
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 More sedimentary →
Explore Chert (Arrowhead Artifact) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
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.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Shale
Shale (clastic sedimentary rock)
sedimentary
Brown Sandstone (River Rock)
Arenite
sedimentary
Shale
Argillaceous sedimentary rock
sedimentary