metamorphic

Foliated metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica gneiss/schist; exact identification requires petrographic examination

AI-generated identification · may be incorrect

Gray, strongly banded and foliated, with visible mica-rich layers and granular lighter minerals; mica has a vitreous to pearly luster. Hardness is roughly 5–7 overall, with excellent planar splitting along mica foliation; specific gravity commonly 2.6–2.8.

Identified September 6, 2026More metamorphic →

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At a glance

Common name: Foliated metamorphic rock, likely gneiss or schist
Scientific name: Quartz–feldspar–mica gneiss/schist; exact identification requires petrographic examination
Category: metamorphic
Identified: September 6, 2026
Method: Standard

AI Estimated Value

Approximately $5–$30 for a common hand specimen; $30–$100 or more for unusually attractive, large, or locality-labeled pieces.

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 shale or another mineral-rich protolith underwent high-grade regional metamorphism, causing recrystallization and mineral segregation into bands. Such rocks range from Precambrian to younger Paleozoic–Mesozoic ages depending on locality.

Uses & applications

Used as crushed aggregate, building stone, landscaping material, and occasionally decorative slabs; attractive pieces may be collected but are generally not gem material.

Geological facts

The pronounced parallel texture records intense pressure and directed heat during mountain building. Dark bands are likely biotite or amphibole, while pale bands commonly contain quartz and feldspar.

Field identification & locations

Identify it by alternating light and dark mineral bands, sparkly mica, and a hard, recrystallized texture rather than sedimentary layering; gneiss is generally coarser and more compositional-band-dominated than schist. Common worldwide in ancient mountain belts, including Canada, Scandinavia, the Appalachian region, India, and Australia.