metamorphic

Polished banded stone, likely gneiss or metasedimentary rock

Banded gneiss (quartz–feldspar–mica assemblage; exact identification requires testing)

AI-generated identification · may be incorrect

Gray-green, pink, and dark mineral bands with a fine-to-medium crystalline texture and subdued satin-to-dull luster; likely Mohs 6–7, with no obvious cleavage on the polished surface. The elongated form appears naturally water-worn or shaped and polished.

Identified September 13, 2026More metamorphic →

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At a glance

Common name: Polished banded stone, likely gneiss or metasedimentary rock
Scientific name: Banded gneiss (quartz–feldspar–mica assemblage; exact identification requires testing)
Category: metamorphic
Identified: September 13, 2026
Method: Standard

AI Estimated Value

About $5–$25 for a small polished common specimen; potentially $30–$75 if unusually attractive, well finished, or provenance-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 preexisting igneous or sedimentary rock underwent high-grade metamorphism, causing minerals to segregate into compositional bands; commonly Precambrian to Paleozoic in age. Rounded surfaces may result from river abrasion or human polishing.

Uses & applications

Used as ornamental stone, cabochons, worry stones, and decorative specimens; not generally valuable as gemstone material.

Geological facts

Pink bands commonly indicate potassium feldspar or quartz, dark streaks may be biotite or amphibole, and green areas may contain chlorite or epidote. A precise name requires a fresh surface, hardness testing, and mineral identification.

Field identification & locations

Look for alternating light and dark mineral bands, granular interlocking crystals, and resistance to scratching by steel. Common in ancient metamorphic terrains worldwide, including Canada, Scandinavia, India, and the United States.