Rocksday

Slate

Shale transformed by low-grade metamorphism into a hard rock that splits into smooth, flat sheets.

Slate specimen
Photo: Dexter Perkins, CC0, via Wikimedia Commons

How to identify slate

  • Splits into thin, flat, smooth sheets.
  • Rings when tapped.
  • Harder than shale.
  • Grains invisible.

Often confused with

Where it's found

  • Gwynedd, Wales
  • Slate Valley, Vermont–New York
  • Galicia, Spain

Uses

Roofing, flooring, pool tables and blackboards.

Rock tumbling

Can be tumbled with care. Makes flat, smooth skipping-stone shapes.

Did you know?

Spain's Galicia region produces most of the world's roofing slate.

Think you could spot it from a blurry close-up?

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