sedimentary
Flint
Silicon dioxide (Microcrystalline Quartz / SiO2)
Hardness of 7 on the Mohs scale, typically brown, grey, or black with a white chalky cortex, waxy to vitreous luster, conchoidal fracture, and amorphous or microcrystalline crystal structure.
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Physical properties
Hardness of 7 on the Mohs scale, typically brown, grey, or black with a white chalky cortex, waxy to vitreous luster, conchoidal fracture, and amorphous or microcrystalline crystal structure.
Formation & geological history
Formed through the chemical replacement of calcium carbonate by silica-rich solutions in chalk or limestone beds during the Cretaceous period, roughly 65 to 145 million years ago.
Uses & applications
Historically used for making stone tools, arrowheads, and striking fire. Today used for decorative landscaping, building construction, and as abrasive material.
Geological facts
Flint found along the Hampshire coast (such as Lepe Country Park) typically originates from the eroding Upper Chalk formations of the Hampshire Basin.
Field identification & locations
Easily identified by its distinctive conchoidal fracture, sharp edges when broken, and often a white outer cortex. Common along southern English beaches and chalk cliffs.
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