sedimentary
Flint
Silicon dioxide (Microcrystalline Quartz, SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically brown or gray in color, waxy to vitreous luster, and displays conchoidal fracture with no true cleavage.
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Physical properties
Hardness of 7 on the Mohs scale, typically brown or gray in color, waxy to vitreous luster, and displays conchoidal fracture with no true cleavage.
Formation & geological history
Forms via the replacement of calcium carbonate by silica-rich solutions in chalk or limestone formations during the Cretaceous period.
Uses & applications
Historically used for making stone tools, arrowheads, and fire-starting flintlocks; currently used in abrasives and decorative landscaping.
Geological facts
Prehistoric humans heavily prized flint for its ability to fracture into razor-sharp edges, making it a critical material for early stone tool technology.
Field identification & locations
Identify in the field by its conchoidal fracture and hardness that scratches glass; commonly found embedded in chalk or limestone cliffs worldwide.
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