sedimentary

Chert flake or weathered flint

Microcrystalline quartz (SiO₂), commonly termed chert or flint

AI-generated identification · may be incorrect

Tan-brown, opaque to slightly translucent, with waxy luster and irregular conchoidal fracture; Mohs hardness about 6.5–7, no cleavage, and very fine-grained cryptocrystalline structure. The sharp ridges and flake-like form may indicate intentional prehistoric knapping.

Identified August 20, 2026More sedimentary →

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At a glance

Common name: Chert flake or weathered flint
Scientific name: Microcrystalline quartz (SiO₂), commonly termed chert or flint
Category: sedimentary
Identified: August 20, 2026
Method: Standard

AI Estimated Value

$1–$10 as an ordinary chert fragment; roughly $20–$200+ if authenticated as an archaeological artifact, depending on age, provenance, workmanship, and legal status.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Chert forms when silica replaces or precipitates within sedimentary rocks, often limestone or chalk, during diagenesis; the specimen’s exact age cannot be determined from the image. If human-worked, its flake scars were produced by percussion or pressure during Stone Age toolmaking.

Uses & applications

Used historically for cutting tools, scrapers, arrowheads, and fire-starting; modern chert is used as aggregate and decorative stone. Archaeological significance may greatly exceed its raw mineral value.

Geological facts

Chert and flint are varieties of microcrystalline quartz; flint commonly refers to dark, high-quality chert, while this piece is unusually weathered and iron-stained.

Field identification & locations

Look for conchoidal fracture, glassy sharp edges, uniform microtexture, and flake scars; common in sedimentary terrains worldwide, especially limestone regions. Distinguishing deliberate knapping from natural breakage requires edge-pattern and platform analysis.