metamorphic

Gray foliated metamorphic rock, likely gneiss or schist

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and testing

AI-generated identification · may be incorrect

Medium- to coarse-grained, gray, with visible wavy foliation and possible mica sparkle; likely Mohs 6–7, vitreous to pearly luster, and no prominent cleavage as a whole rock. Quartz and feldspar provide hardness, while mica produces the layered texture.

Identified August 18, 2026More metamorphic →

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At a glance

Common name: Gray foliated metamorphic rock, likely gneiss or schist
Scientific name: Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and testing
Category: metamorphic
Identified: August 18, 2026
Method: Standard

AI Estimated Value

Approximately $5–$25 for a common field specimen; $30–$100 if unusually attractive, polished, or demonstrably from a notable locality.

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 preexisting igneous or sedimentary rock underwent high-temperature and pressure metamorphism, probably during a mountain-building event; its precise geological age cannot be determined from the photograph.

Uses & applications

Common varieties are used as landscaping stone, paving, building stone, and aggregate; attractive pieces may be collected, but this specimen appears ordinary and unpolished.

Geological facts

The pronounced compositional banding or alignment indicates deformation and recrystallization rather than simple layering. If mica-rich and easily split, it is schist; if quartz- and feldspar-rich with compositional bands, it is gneiss.

Field identification & locations

Common in ancient continental shields and metamorphic mountain belts worldwide. Identify with a fresh break, streakless silicate minerals, hardness testing, and checking whether foliation splits readily; do not confuse it with foliated basalt or slate.