sedimentary

Flint (chert), possibly fossil-bearing

Microcrystalline quartz (SiO₂), chalcedony/flint variety

AI-generated identification · may be incorrect

Brown to tan, opaque, dull-to-waxy luster, very fine-grained and conchoidally fractured; Mohs hardness about 7, no cleavage, specific gravity ~2.6. The pale interior and curved fracture surfaces are consistent with weathered flint, though the image alone cannot confirm a fossil.

Identified August 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms by silica replacement or accumulation within marine limestone and chalk, commonly during the Cretaceous; later weathering releases resistant nodules. This is geologically plausible near 47.6°N, 19.3°E, where Cenozoic sediments and redeposited flint-like chert can occur.

Uses & applications

Used historically for stone tools and fire-starting, and occasionally as aggregate or lapidary material; rarely valuable as a small specimen.

Geological facts

Fresh flint edges are extremely sharp and can produce sparks with steel. A white weathering cortex or rind commonly develops around darker interiors.

Field identification & locations

Test for glass-scratching hardness and inspect fresh breaks for a smooth, shell-like fracture; avoid destructive testing if it may be archaeological. Likely regional alternatives include siliceous chert or silicified limestone.