sedimentary

Flint (chert), likely a worked stone flake

Microcrystalline quartz (SiO₂); cryptocrystalline variety of quartz

AI-generated identification · may be incorrect

Hardness about 7 Mohs; dark gray-brown with a waxy to dull luster, very fine-grained structure, and conchoidal fracture. The sharp, irregular edges and flake scars suggest it may have been intentionally knapped.

Identified October 4, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms as silica-rich nodules or layers in sedimentary rocks, commonly limestone or chalk, through silica precipitation and replacement. Flint deposits range from Paleozoic to Cenozoic in age; the specimen’s specific age cannot be determined from the image.

Uses & applications

Historically used for stone tools and fire-starting; today collected as a geological or archaeological specimen and sometimes used decoratively.

Geological facts

Flint’s sharp conchoidal edges made it an important prehistoric tool material. A worked flake cannot be confirmed from appearance alone; archaeological context and close examination matter.

Field identification & locations

Look for a very fine texture, hard surface, and curved, shell-like fracture marks; flint is common in chalk and limestone regions. This small piece appears chipped, but its provenance is unknown.