sedimentary

Polished banded pebble, likely quartz-veined chert or jasper

Microcrystalline quartz (SiO₂), possibly chert/jasper with a quartz or chalcedony vein

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; dark gray-brown, with white irregular vein bands and a dull to waxy polished luster. Microcrystalline quartz has no visible cleavage and typically breaks conchoidally; exact identification requires testing.

Identified September 13, 2026More sedimentary →

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At a glance

Common name: Polished banded pebble, likely quartz-veined chert or jasper
Scientific name: Microcrystalline quartz (SiO₂), possibly chert/jasper with a quartz or chalcedony vein
Category: sedimentary
Identified: September 13, 2026
Method: Standard

AI Estimated Value

Approximately $5–$25 as a common polished pebble; unusual pattern, provenance, or professional lapidary work may raise it to $30–$75.

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 as silica-rich sediment or replacement material, later cut by fractures filled with quartz or chalcedony; age cannot be determined from the photograph. Such pebbles commonly originate in sedimentary or hydrothermal environments and are rounded by erosion.

Uses & applications

Primarily a lapidary or decorative specimen, suitable for polishing, cabochons, worry stones, and small carvings; not generally valuable as construction stone.

Geological facts

The pale bands may be quartz, chalcedony, or calcite rather than true bedding. A steel file should not scratch quartz-rich material, while calcite veins fizz weakly in dilute hydrochloric acid.

Field identification & locations

Common in gravel beds, stream deposits, and areas with chert or quartz-vein outcrops. Confirm with hardness, streak, acid reaction, and a close inspection of the vein minerals.