sedimentary

Chert or jasper (iron-stained, brecciated variety)

Microcrystalline quartz (SiO₂), commonly termed jasper when strongly colored by iron oxides

AI-generated identification · may be incorrect

Typically 6.5–7 Mohs, opaque, earthy red-brown, gray, and yellow coloration, with dull to waxy luster and no visible cleavage. The specimen shows dense, fine-grained silica with irregular fractures and iron-oxide staining.

Identified September 15, 2026More sedimentary →

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At a glance

Common name: Chert or jasper (iron-stained, brecciated variety)
Scientific name: Microcrystalline quartz (SiO₂), commonly termed jasper when strongly colored by iron oxides
Category: sedimentary
Identified: September 15, 2026
Method: Standard

AI Estimated Value

About $2–$15 for a rough hand specimen; attractive patterned or polish-quality material may sell for $20–$100.

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

Forms by chemical or biochemical precipitation of silica, often replacing limestone or accumulating as bedded chert; iron oxides produce the red, brown, and yellow colors. Its exact geological age cannot be determined from the photograph and may range from Paleozoic to Cenozoic.

Uses & applications

Used as lapidary material, cabochons, beads, carvings, and decorative stone; ordinary pieces have little industrial value compared with higher-grade silica deposits.

Geological facts

Jasper is technically a variety of chert distinguished mainly by abundant impurities and strong coloration. The mottled appearance may reflect brecciation, veining, or partial replacement by silica and iron minerals.

Field identification & locations

Identify it by its opaque, very fine texture, conchoidal fracture, hardness sufficient to scratch glass, and lack of fizz in dilute acid. Common occurrences include sedimentary basins and hydrothermal replacement zones worldwide.