sedimentary
Flint
SiO2 (Microcrystalline Quartz)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and typically dark gray to brown or black color.
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Physical properties
Hardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and typically dark gray to brown or black color.
Formation & geological history
Formed by the chemical replacement of calcium carbonate in limestone by silica-rich groundwater during the Cretaceous period.
Uses & applications
Historically used for making stone tools and striking fire; currently used in decorative gravel and abrasive industries.
Geological facts
Flint features prominent thermal fracturing and smooth conchoidal surfaces that make it exceptionally sharp when chipped.
Field identification & locations
Found widely embedded in chalk or limestone formations; identified by its waxy sheen and razor-sharp edges.
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Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
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Arenite (if sandstone)
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Shale
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Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
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