RocksdaySchist vs Slate
How to tell them apart
A shimmering metamorphic rock full of aligned mica flakes, often studded with garnets.
Photo: Michael C. Rygel, CC BY-SA 3.0
Shale transformed by low-grade metamorphism into a hard rock that splits into smooth, flat sheets.
Photo: Dexter Perkins, CC0
Key differences
- Slate's grains are invisible and it splits flat.
- Schist glitters with visible mica flakes.
Side by side
| Property | Schist | Slate |
|---|---|---|
| Type | Metamorphic rock | Metamorphic rock |
| Mohs hardness | 4–5 | 3–4 |
| Luster | Glittery | Dull to faint sheen |
| Colors | Silver, Gray, Green | Gray, Black, Green, Purple |
| Crystal system / structure | Medium-grained, foliated | Very fine, foliated (slaty cleavage) |
| Specific gravity | 2.7–3 | 2.7–2.8 |
| Found in | Manhattan, New York; Grand Canyon (Vishnu Schist) | Gwynedd, Wales; Slate Valley, Vermont–New York |
Properties that are the same for both are grayed out.
How to identify schist
- Glitters with visible mica.
- Wavy, flaky layers.
- Often contains red garnets or other crystals.
- Splits unevenly along layers.
Structure: Medium-grained, foliated
Full Schist guide →How to identify slate
- Splits into thin, flat, smooth sheets.
- Rings when tapped.
- Harder than shale.
- Grains invisible.
Structure: Very fine, foliated (slaty cleavage)
Full Slate guide →More comparisons
Could you tell them apart from a blurry close-up?
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