RocksdayGranite vs Marble
The quickest way to tell Granite from Marble: Granite scratches glass (Mohs 6–7); Marble can't (Mohs 3–4).
A coarse-grained rock that cooled slowly deep underground, made of quartz, feldspar and mica or hornblende.
Photo: The stone gate, CC BY-SA 4.0
Limestone recrystallized by heat and pressure into a mosaic of interlocking calcite grains.
Photo: Zyance, CC BY-SA 2.5
Quick tests
- Scratch glass: Granite scratches glass (Mohs 6–7); Marble can't (Mohs 3–4).
- Acid (vinegar or dilute HCl): Marble fizzes; Granite doesn't.
Key differences
- Marble fizzes in acid, a knife scratches it, and it has no quartz grains.
- Granite is much harder, does not fizz, and shows quartz, feldspar and dark specks.
Side by side
| Property | Granite | Marble |
|---|---|---|
| Type | Igneous rock | Metamorphic rock |
| Mohs hardness | 6–7 | 3–4 |
| Luster | Granular, sparkly | Sugary sparkle |
| Colors | Pink, Gray, White, Black | White, Gray, Pink, Green |
| Crystal system / structure | Coarse-grained (phaneritic) | Interlocking crystals (non-foliated) |
| Specific gravity | 2.63–2.75 | 2.6–2.9 |
| Found in | Sierra Nevada, California; Stone Mountain, Georgia | Carrara, Italy; Yule, Colorado |
Properties that are the same for both are grayed out.
How to identify granite
- Speckled with interlocking grains you can see without a lens.
- Glassy gray quartz plus pink or white blocky feldspar.
- Black specks of mica or hornblende.
- Hard, with no layering or banding.
Structure: Coarse-grained (phaneritic)
Full Granite 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
Frequently asked questions
What is the difference between granite and marble?
Granite is an igneous rock with a Mohs hardness of about 6–7 and a granular, sparkly luster, usually pink, gray, white or black. Marble is a metamorphic rock with a Mohs hardness of about 3–4 and a sugary sparkle luster, usually white, gray, pink or green.
How can you tell granite from marble?
Granite scratches glass (Mohs 6–7); Marble can't (Mohs 3–4). Marble fizzes; Granite doesn't. Marble fizzes in acid, a knife scratches it, and it has no quartz grains. Granite is much harder, does not fizz, and shows quartz, feldspar and dark specks.
Could you tell them apart from a blurry close-up?
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