metamorphic

Dark metamorphic rock, likely schist or slate fragment

Indeterminate foliated metamorphic rock; possibly mica schist or slate

AI-generated identification · may be incorrect

Dark gray to black, fine- to medium-grained, dull to slightly silky luster with planar foliation and irregular fractures. Typical hardness is about 3–6 Mohs, depending on mica, chlorite, quartz, and graphite content; exact identification requires a fresh surface and tests.

Identified September 19, 2026More metamorphic →

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At a glance

Common name: Dark metamorphic rock, likely schist or slate fragment
Scientific name: Indeterminate foliated metamorphic rock; possibly mica schist or slate
Category: metamorphic
Identified: September 19, 2026
Method: Standard

AI Estimated Value

About $1–$10 as an unidentified common specimen; up to $10–$30 if confirmed as an attractive or locality-labeled schist/slate piece.

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 mudstone was subjected to heat and pressure during regional metamorphism, commonly during mountain building. Its age cannot be determined from the photograph and depends on the source formation.

Uses & applications

Used locally as construction stone, roofing slate, aggregate, or landscape material; this small specimen has little commercial value.

Geological facts

The visible layered or platy texture is characteristic of foliation, caused by aligned mineral grains under directed pressure. A graphite-rich variety may leave a faint gray streak, while mica-rich varieties may show sparkling flakes.

Field identification & locations

Common in metamorphic belts worldwide, including Appalachians, Scotland, Wales, Scandinavia, and the Alps. Look for splitting along parallel planes; a glassy quartz-rich surface or strong sparkle would help distinguish schist from slate.