metamorphic

Banded metamorphic rock, likely gneiss or metasedimentary slate

Quartz–feldspar–mica gneiss (tentative), possibly containing iron-oxide veins

AI-generated identification · may be incorrect

Gray, tan, and rusty-orange layered bands with a granular to foliated texture; likely quartz and feldspar with mica and hematite/goethite staining. Estimated hardness 5.5–7, vitreous to dull luster, no obvious cleavage visible; specific gravity roughly 2.6–2.8.

Identified September 8, 2026More metamorphic →

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At a glance

Common name: Banded metamorphic rock, likely gneiss or metasedimentary slate
Scientific name: Quartz–feldspar–mica gneiss (tentative), possibly containing iron-oxide veins
Category: metamorphic
Identified: September 8, 2026
Method: Standard

AI Estimated Value

About $1–$15 for an ordinary loose specimen; $20–$75 if unusually attractive, polished, or clearly 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

Formed when layered sedimentary or volcanic material was buried, heated, and compressed, producing compositional banding and foliation. The orange zones are probably iron-oxide-rich fractures or altered layers; exact age cannot be determined from the photograph.

Uses & applications

Useful mainly as a teaching or collecting specimen; similar gneiss is used as dimension stone, landscaping stone, aggregate, and occasionally decorative slabs.

Geological facts

The specimen is clearly geological, but the image does not resolve individual minerals well enough for a precise species identification. Its banding favors gneiss or strongly metamorphosed sedimentary rock over a typical igneous rock.

Field identification & locations

In northwestern Pennsylvania, glacially transported metamorphic cobbles are plausible, though local bedrock is largely sedimentary. Check for alternating light/dark mineral bands, mica flakes, and whether it scratches glass; a streak or fresh broken surface would improve identification.