sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
Hardness: 6.5-7 Mohs; Color: Gray, tan, brown with waxy luster; Crystal Structure: Microcrystalline/Cryptocrystalline; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 6
- Color
- Gray, tan, brown with waxy luster
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 Mohs; Color: Gray, tan, brown with waxy luster; Crystal Structure: Microcrystalline/Cryptocrystalline; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Formed by the accumulation of siliceous remains of organisms (like diatoms or radiolarians) or through chemical precipitation in marine or groundwater environments.
Uses & applications
Historically used for stone tools and starting fires; currently used in construction aggregate and as a collector's item.
Geological facts
Flint is a variety of chert that has been vital to human history, being the primary material for arrowheads and scrapers during the Stone Age.
Field identification & locations
Identify by its characteristic shell-like (conchoidal) fracture patterns and ability to scratch glass. Commonly found in limestone or chalk beds.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary