sedimentary
Chert (Yellow Jasper / Flint)
Microcrystalline Quartz (SiO2)
Mohs hardness of 6.5-7, yellowish-brown to tan color, waxy to dull luster, conchoidal fracture, lack of cleavage, specific gravity around 2.65.
Identified More sedimentary →
Explore Chert (Yellow Jasper / Flint) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness of 6.5-7, yellowish-brown to tan color, waxy to dull luster, conchoidal fracture, lack of cleavage, specific gravity around 2.65.
Formation & geological history
Formed by the precipitation of silica-rich fluids in sedimentary rock layers or through the accumulation of biogenic siliceous oozes over millions of years.
Uses & applications
Historically used for making stone tools, arrowheads, and fire-starting flints. Currently used in lapidary work, decorative landscaping, and as a mineral specimen.
Geological facts
Chert and flint were among the first materials used by early humans for tools due to the sharp edges created by its conchoidal fracture.
Field identification & locations
Identified in the field by its hardness (scratches glass), smooth waxy feel, and characteristic curved (conchoidal) fracture surfaces. Commonly found in limestone and chalk formations worldwide.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale
Argillaceous sedimentary rock
sedimentary
Mudstone
Argillite / Siliciclastic sedimentary rock
sedimentary