sedimentary
Chert (Flint)
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 7 on Mohs scale. Color: Brownish-tan to grey, opaque. Luster: Waxy to dull. Fracture: Distinctive conchoidal fracture with sharp edges. Microcrystalline quartz structure.
- Hardness
- 7 on Mohs scale
- Color
- Brownish-tan to grey, opaque
- Luster
- Waxy to dull
Identified More sedimentary →
Explore Chert (Flint) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale. Color: Brownish-tan to grey, opaque. Luster: Waxy to dull. Fracture: Distinctive conchoidal fracture with sharp edges. Microcrystalline quartz structure.
Formation & geological history
Formed through the accumulation of siliceous oozes or chemical precipitation of silica in marine sediment environments, often replacing limestone or chalk beds.
Uses & applications
Historically used for making stone tools, arrowheads, and flintlock firearms due to its sharp conchoidal fracture. Today used as road aggregate and ornamental specimens.
Geological facts
Chert was one of the earliest raw materials utilized by prehistoric humans to forge tools, weapons, and spark fires due to its intense hardness and predictable fracturing pattern.
Field identification & locations
Look for a microcrystalline texture, dull-to-waxy luster, high hardness (scratches glass), and characteristic curved conchoidal fractures. Extremely common in sedimentary basins worldwide.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary