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
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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.
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