sedimentary

Polished brecciated iron-rich rock, possibly jasper or chert

Brecciated silica-rich rock; likely microcrystalline quartz (SiO₂) with iron-oxide minerals

AI-generated identification · may be incorrect

Typically hardness about 6.5–7 Mohs, earthy brown, gray, black, and rusty-red colors, and a dull to waxy or glassy luster. The irregular fragments and iron-stained matrix suggest brecciation; individual crystals are mostly microscopic, with no obvious cleavage.

Identified September 3, 2026More sedimentary →

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At a glance

Common name: Polished brecciated iron-rich rock, possibly jasper or chert
Scientific name: Brecciated silica-rich rock; likely microcrystalline quartz (SiO₂) with iron-oxide minerals
Category: sedimentary
Identified: September 3, 2026
Method: Standard

AI Estimated Value

About $3–$15 for a common polished specimen; $20–$75 if unusually attractive, well-polished, or locality-documented.

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

Likely formed when silica-rich sediment or volcanic material fractured and was cemented by quartz and iron oxides, then later weathered and rounded. Its exact geological age and locality cannot be determined from the photograph alone.

Uses & applications

Used as a decorative stone, tumbled specimen, lapidary material, and occasionally in cabochons or small carvings; not generally important as a construction stone.

Geological facts

The metallic-looking dark areas may be hematite or magnetite, while orange-brown patches are likely limonite/goethite. A streak, hardness, magnetism, and acid tests would substantially improve identification.

Field identification & locations

Look for a very hard surface that scratches glass, a white-to-reddish streak, and possible weak magnetism; jasper/chert commonly occurs in sedimentary beds, volcanic terrains, and gravel deposits worldwide.