metamorphic

Mica-rich metamorphic rock, likely phyllite or mica schist

Quartz–muscovite phyllite/schist; commonly dominated by muscovite mica, quartz, and minor feldspar

AI-generated identification · may be incorrect

Gray-gold, foliated, sparkly surface with a silky to pearly luster; mica flakes reflect light. Hardness is roughly 2–3 for exposed muscovite but about 5–7 for the quartz-rich mass; typically splits along foliation and has no obvious crystal faces.

Identified September 13, 2026More metamorphic →

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At a glance

Common name: Mica-rich metamorphic rock, likely phyllite or mica schist
Scientific name: Quartz–muscovite phyllite/schist; commonly dominated by muscovite mica, quartz, and minor feldspar
Category: metamorphic
Identified: September 13, 2026
Method: Standard

AI Estimated Value

About $2–$15 for a common hand specimen; $20–$50 for an unusually attractive, labeled specimen.

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 buried, compressed, and heated during regional metamorphism, commonly during mountain building. Its exact geological age cannot be determined from the photograph.

Uses & applications

Used locally as decorative stone, aggregate, landscaping material, or roofing/slate-like products; attractive specimens may be collected, but it is generally not a gemstone.

Geological facts

The glitter comes from aligned mica plates rather than metallic particles. A strong silky sheen and tendency to split into thin layers favor phyllite; coarser visible mica favors mica schist.

Field identification & locations

Common in metamorphic belts worldwide, including the Appalachians, Rocky Mountains, Alps, and Himalayas. Test a fresh surface for flexible mica flakes and compare its foliation; a definitive identification requires a hand-lens or thin-section examination.