sedimentary
Fossiliferous Flint
Microcrystalline Quartz (SiO2) with Echinoid Fossil
Hardness of 7 on the Mohs scale, conchoidal fracture, waxy to vitreous luster, colors range from greyish-brown to tan with a weathered cortex.
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Physical properties
Hardness of 7 on the Mohs scale, conchoidal fracture, waxy to vitreous luster, colors range from greyish-brown to tan with a weathered cortex.
Formation & geological history
Formed in marine environments through the replacement of calcium carbonate in limestone by silica-rich fluids, frequently encasing ancient marine fossils such as echinoids (sea urchins) during the Cretaceous period.
Uses & applications
Used historically for primitive stone tools and fire-starting; nowadays collected by fossil and mineral enthusiasts.
Geological facts
Flint nodules often preserve delicate ancient marine life in exquisite detail due to the rapid replacement of organic material by silica.
Field identification & locations
Can be identified in the field by its conchoidal fracture, sharp edges, characteristic weathered outer rind, and embedded fossil imprints. Commonly found in chalk formations and gravel deposits.
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