sedimentary
Chert (Iron-Stained)
Chert (Silicon Dioxide, SiO2)
AI-generated identification · may be incorrectHardness: 7 (Mohs scale), Color: Cream with orange-brown iron staining, Luster: Waxy to dull, Crystal Structure: Microcrystalline/Cryptocrystalline, Cleavage: None (conchoidal fracture), Specific Gravity: 2.6-2.7
Identified More sedimentary →
Explore Chert (Iron-Stained) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale), Color: Cream with orange-brown iron staining, Luster: Waxy to dull, Crystal Structure: Microcrystalline/Cryptocrystalline, Cleavage: None (conchoidal fracture), Specific Gravity: 2.6-2.7
Formation & geological history
Formed from the accumulation of silica-rich organic remains or through the chemical precipitation of silica in marine environments. Iron staining occurs through groundwater leaching.
Uses & applications
Historically used for arrowheads and tools; currently used in decorative landscaping and as an industrial abrasive.
Geological facts
Chert is so hard it can strike sparks against steel. Often called flint when found in chalk or marl, it is one of the most durable sedimentary rocks.
Field identification & locations
Identify by its 'slick' waxy feel, conchoidal (shell-like) fracture edges, and inability to be scratched by a steel knife. Commonly found in riverbeds and limestone outcrops.
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