sedimentary
Chert / Flint
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 on Mohs scale. Color: Gray, purple-tinted, brown, to translucent white. Luster: Waxy to dull. Fracture: Conchoidal with sharp edges. Microcrystalline structure.
- Hardness
- 6
- Color
- Gray, purple-tinted, brown, to translucent white
- 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: 6.5-7 on Mohs scale. Color: Gray, purple-tinted, brown, to translucent white. Luster: Waxy to dull. Fracture: Conchoidal with sharp edges. Microcrystalline structure.
Formation & geological history
Formed through biochemical and chemical precipitation of microcrystalline quartz, often in marine environments within limestone or chalk beds as nodules or layers.
Uses & applications
Historically used for making stone tools, arrowheads, and spark-striking flint. Today used in lapidary art, decorative stone, and gravel aggregate.
Geological facts
Chert fractures with a distinct conchoidal (shell-like) fracture, producing razor-sharp edges that were crucial for ancient stone tool production.
Field identification & locations
Look for smooth, waxy surfaces with curved, glass-like sharp fractures. Highly durable and non-porous compared to surrounding limestone or dolomite matrix.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary