metamorphic

Weathered gray metamorphic rock, likely schist or gneiss

Micaceous quartz-feldspar schist/gneiss; exact identification requires a fresh surface and testing

AI-generated identification · may be incorrect

Hardness about 5–7 Mohs; gray, coarse-grained, granular to weakly foliated, with dull to vitreous luster. Likely contains quartz, feldspar, mica, and possibly dark amphibole; visible foliation appears subtle and weathered.

Identified September 7, 2026More metamorphic →

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At a glance

Common name: Weathered gray metamorphic rock, likely schist or gneiss
Scientific name: Micaceous quartz-feldspar schist/gneiss; exact identification requires a fresh surface and testing
Category: metamorphic
Identified: September 7, 2026
Method: Standard

AI Estimated Value

About $1–$10 as an ordinary loose specimen; potentially $20–$50 if unusually attractive, labeled, or part of a documented 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 shale or igneous rock was subjected to elevated pressure and temperature during regional metamorphism, commonly hundreds of millions to billions of years ago. Weathering has rounded and stained the exposed surface.

Uses & applications

Used locally as crushed aggregate, road stone, landscaping rock, and occasionally as building or decorative stone; generally not gem-quality.

Geological facts

The apparent dark streaks and planar fabric may represent biotite or amphibole-rich layers. A fresh break, hand lens, streak, acid, and hardness tests would distinguish schist from gneiss or other gray metamorphic rocks.

Field identification & locations

Look for aligned mica flakes, compositional banding, and quartz-feldspar grains; common in mountain belts and exposed continental basement. Likely local fieldstone rather than a distinctive collectible specimen.