Phyllite identification and geology

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• Browse all rock identification entries — Compare this entry with the complete GeoMiner rocks collection.
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• Slate
• Schist
• Shale
• Foliated rocks — Place this specimen in a broader field-identification workflow.
• Slate vs Phyllite — Compare observable properties and safer field tests.
• Phyllite vs Schist — Compare observable properties and safer field tests.

Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner

GeoMiner

Last updated

2026-03-30T14:39:08.094233+00:00

Review status

Published; not independently peer-reviewed

• Rocks — U.S. National Park Service. Authoritative overview of rock groups, the rock cycle, and geologic processes.
• Can you identify my rock or mineral? — U.S. Geological Survey. Identification limitations and routes to in-person professional verification.

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Common questions

What is Phyllite?

Fine-grained foliated metamorphic rock intermediate between slate and schist. Displays a characteristic silky sheen from microscopic mica.

How can you identify Phyllite?

Compare several properties rather than relying on colour alone. This entry records rock type: Metamorphic Foliated; texture: Foliated phyllitic; grain size: Fine microscopic mica; common minerals: Muscovite, Chlorite, Quartz, Feldspar. Confirm an important identification with additional field tests or qualified laboratory work.

How does Phyllite form?

Forms from low-grade regional metamorphism of shale/mudstone at slightly higher temperatures and pressures than slate.

Where is Phyllite commonly found?

Found in regional metamorphic belts worldwide; Appalachians, Alps, Scottish Highlands.

What is Phyllite commonly confused with?

Phyllite may be confused with Slate, Schist, Shale. Compare multiple diagnostic properties because colour and surface appearance can overlap.