Flint or chert flake

Opaque tan-brown stone with a dull to slightly waxy luster, conchoidal fracture, sharp flake edges, and a darker rough outer cortex. Hardness is about 6.5–7 Mohs; no visible cleavage; specific gravity approximately 2.60.

Chert forms when silica replaces or accumulates within marine or freshwater sediment, commonly during the Cretaceous or other Phanerozoic periods; the exact age cannot be determined from the photograph. Its triangular shape and bulbous fracture surface strongly suggest intentional prehistoric knapping, though natural breakage is possible.

Historically used for cutting tools, spear and arrow points, fire-starting, and scraping; attractive pieces may be collected as archaeological lithics or geological specimens. It has little commercial value as ordinary raw material.

The sharp edge results from conchoidal fracture, a diagnostic property of quartz-rich stone. Dark markings along the base may be cortex, impurities, or weathering rather than a distinct fossil.

Identify it by testing hardness against glass, looking for a waxy surface and curved fracture ripples, and checking for uniform microcrystalline texture; avoid destructive testing if archaeological origin is possible. Chert is common in limestone and chalk regions worldwide, including Europe, North America, and the Middle East.