metamorphic

Schist, possibly garnet-mica schist

Mica schist; chiefly muscovite/biotite mica, quartz, and feldspar, with possible garnet or sulfide grains

AI-generated identification · may be incorrect

Gray-brown, strongly foliated and sparkly with platy mica; uneven cleavage and a layered texture. Typical hardness is about 2–3 for mica-rich surfaces and 6–7 for quartz; specific gravity commonly 2.6–2.9.

Identified September 21, 2026More metamorphic →

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At a glance

Common name: Schist, possibly garnet-mica schist
Scientific name: Mica schist; chiefly muscovite/biotite mica, quartz, and feldspar, with possible garnet or sulfide grains
Category: metamorphic
Identified: September 21, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a common hand specimen; $10–$40 if it contains well-formed garnets or unusually attractive mineralization.

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 clay-rich sediment was subjected to elevated heat and directed pressure during regional metamorphism, commonly during mountain building. The specimen’s exact geological age cannot be determined from the photograph.

Uses & applications

Used locally as decorative stone, landscaping material, and occasionally for architectural veneer; attractive mica-rich pieces are collected, though this small rough specimen has limited commercial value.

Geological facts

The glitter comes from aligned mica flakes, which produce schistosity. Dark metallic-looking patches may be biotite, graphite, or sulfide minerals, while pale grains are likely quartz or feldspar.

Field identification & locations

Identify it by its foliated, glittery layers and tendency to split along mica-rich planes; a magnifier, streak test, and hardness test can distinguish sulfides or graphite. Common in metamorphic mountain belts worldwide.