metamorphic

Reddish foliated metamorphic rock, likely phyllite

Phyllite, typically quartz–mica–chlorite with iron-oxide staining

AI-generated identification · may be incorrect

Fine-grained, strongly foliated and splits into thin layers; silky to dull sheen, salmon-red to brown color, irregular cleavage, and approximate Mohs hardness 2–4. The reddish color likely reflects hematite or other iron oxides.

Identified September 11, 2026More metamorphic →

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Physical properties

Formation & geological history

Formed when shale or mudstone underwent low-grade regional metamorphism, commonly during mountain building. Exact age cannot be determined visually; rocks of this type are widespread in Taiwan’s rapidly uplifted metamorphic belts.

Uses & applications

Used mainly as a decorative or landscaping stone, aggregate, and occasionally roofing or wall stone; this specimen has modest collector value.

Geological facts

The visible planar fabric and folded, flaky texture distinguish phyllite from ordinary claystone. It may also be fine-grained schist or altered slate, which cannot be separated confidently without thin-section or hardness testing.

Field identification & locations

Likely compatible with the mountainous terrain near 24.0°N, 121.6°E. Test whether it splits along foliation, leaves a white streak, and scratches glass; a silky sheen favors phyllite, while visible mica flakes and hardness above 4 favor schist.