sedimentary
Chert/Flint Nodule
Microcrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness of 6.5-7 on the Mohs scale, typically brown, tan, gray, or black, waxy or dull luster, microcrystalline structure, conchoidal fracture.
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Physical properties
Hardness of 6.5-7 on the Mohs scale, typically brown, tan, gray, or black, waxy or dull luster, microcrystalline structure, conchoidal fracture.
Formation & geological history
Formed as a chemical sedimentary rock, often from the accumulation of silica-rich marine micro-organisms or through chemical precipitation in limestone or chalk beds.
Uses & applications
Historically used for making stone tools (arrowheads, scrapers) and starting fires. Currently used in road construction or as gravel.
Geological facts
Because it breaks with a conchoidal fracture, it can produce very sharp edges, making it one of the most important materials for early human tools.
Field identification & locations
Identify by its hardness (scratches glass), smooth waxy appearance, and conchoidal fracture. Commonly found in riverbeds, glacial deposits, and sedimentary rock formations.
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