sedimentary
Chert
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and colors ranging from white to gray, brown, and black.
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Physical properties
Hardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and colors ranging from white to gray, brown, and black.
Formation & geological history
Formed through the chemical precipitation of silica from aqueous solutions or the accumulation of siliceous skeletal remains of marine organisms in deep-sea environments.
Uses & applications
Historically used by early humans for stone tools and weapons due to its sharp conchoidal fracture; occasionally used in decorative landscaping and lapidary work.
Geological facts
Chert forms nodules or beds within limestone and chalk formations and includes varieties like flint, jasper, and agate.
Field identification & locations
Identify in the field by its extreme hardness, smooth waxy texture, and characteristic sharp conchoidal breakages. Commonly found in limestone deposits worldwide.
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Other sedimentary specimens
Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion
Calcareous concretion; exact fossil and host-rock composition are not identifiable from the image
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone
Arenite
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary