RocksdayDolostone vs Marble
How to tell them apart
A limestone-like rock made of the mineral dolomite rather than calcite.
Photo: James St. John, CC BY 2.0
Limestone recrystallized by heat and pressure into a mosaic of interlocking calcite grains.
Photo: Zyance, CC BY-SA 2.5
Quick tests
- Acid (vinegar or dilute HCl): Dolostone fizzes weakly, or only when powdered or warmed; Marble doesn't.
Key differences
- Marble is coarser and sparkly.
Side by side
| Property | Dolostone | Marble |
|---|---|---|
| Type | Sedimentary rock | Metamorphic rock |
| Mohs hardness | 3.5–4 | 3–4 |
| Luster | Dull to sugary | Sugary sparkle |
| Colors | Gray, White, Brown | White, Gray, Pink, Green |
| Crystal system / structure | Crystalline carbonate | Interlocking crystals (non-foliated) |
| Specific gravity | 2.8–2.9 | 2.6–2.9 |
| Found in | The Dolomites, Italy; Niagara Escarpment | Carrara, Italy; Yule, Colorado |
Properties that are the same for both are grayed out.
How to identify dolostone
- Gray to cream, often sugary.
- Fizzes only weakly — or only when powdered.
- Weathers to a buff color.
Structure: Crystalline carbonate
Full Dolostone guide →How to identify marble
- Sparkly, sugary crystals on broken surfaces.
- Fizzes in acid.
- A knife scratches it.
- Often swirled or veined.
Structure: Interlocking crystals (non-foliated)
Full Marble guide →More comparisons
Could you tell them apart from a blurry close-up?
Play today's Rocksday