sedimentary
Chert (Brecciated or Veined)
Microcrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness 7, waxy to dull luster, conchoidal fracture, extremely fine-grained, color ranging from tan/grey to blue-grey with white quartz veining.
Identified More sedimentary →
Explore Chert (Brecciated or Veined) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness 7, waxy to dull luster, conchoidal fracture, extremely fine-grained, color ranging from tan/grey to blue-grey with white quartz veining.
Formation & geological history
Formed from the accumulation of silica-rich microfossils or chemical precipitation in marine environments. This specific piece shows evidence of tectonic stress resulting in fractures later filled with secondary minerals.
Uses & applications
Historically used for stone tools due to sharp edges; currently used for road ballast, landscaping, and occasionally as lapidary material when colorful.
Geological facts
Chert is so durable it often survives long after other surrounding rocks have weathered away. It is often synonymous with 'flint' in common parlance.
Field identification & locations
Identify by its extreme hardness (scratches glass) and smooth, shell-like fracture surfaces. Found worldwide in sedimentary bedding planes and as nodules in limestone.
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