RocksdayCoal vs Lignite
How to tell them apart
A rock formed from buried, compressed plant material — ancient swamp forests turned to stone.
Photo: Amcyrus2012, CC BY 4.0
Soft brown coal, the youngest and lowest grade, often with visible woody texture.
Photo: James St. John, CC BY 2.0
Key differences
- Bituminous coal is blacker, harder and shinier.
Side by side
| Property | Coal | Lignite |
|---|---|---|
| Type | Sedimentary rock | Sedimentary rock |
| Mohs hardness | 2–3 | 1–2 |
| Luster | Dull to submetallic | Dull |
| Colors | Black, Brown | Brown, Black |
| Crystal system / structure | Organic, layered | Organic, woody |
| Specific gravity | 1.1–1.8 | 1.1–1.3 |
| Found in | Powder River Basin, Wyoming; Appalachia | Rhineland, Germany; Latrobe Valley, Australia |
Properties that are the same for both are grayed out.
How to identify coal
- Black and very light for a rock.
- Leaves black dust on hands.
- Layered, with blocky or curved breaks.
- Burns.
Structure: Organic, layered
Full Coal guide →How to identify lignite
- Brown-black and crumbly.
- Wood grain sometimes visible.
- Very light; cracks as it dries.
Structure: Organic, woody
Full Lignite guide →More comparisons
Could you tell them apart from a blurry close-up?
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