metamorphic

Slate

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz

AI-generated identification · may be incorrect

Typically dark gray, dull to slightly silky, with very fine grains and strong slaty cleavage; hardness is about 3–4 Mohs. The specimen appears rough and layered, though its cartoon-like presentation limits reliable visual identification.

Identified September 25, 2026More metamorphic →

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Physical properties

Formation & geological history

Forms when shale or mudstone is subjected to low-grade metamorphism, producing flat cleavage planes; slate occurs in rocks spanning a wide range of geological ages.

Uses & applications

Used for roofing, floor and paving tiles, blackboards, and decorative stone; attractive pieces may be collected, but this example’s market value cannot be judged from the image.

Geological facts

Slate splits into thin, relatively flat sheets because metamorphism aligns tiny platy minerals.

Field identification & locations

Look for a fine-grained texture and planar sheets that split cleanly; common slate regions include Wales, Vermont, and Spain. The image is stylized, so slate identification is tentative.