RocksdayGneiss vs Granite
How to tell them apart
A high-grade metamorphic rock with bold light and dark bands, formed under intense heat and pressure.
Photo: No machine-readable author provided. Siim assumed (based on copyright claims)., CC BY-SA 3.0
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
Key differences
- Granite has the same minerals but no banding.
- Gneiss has the same minerals arranged in bands or stripes.
Side by side
| Property | Gneiss | Granite |
|---|---|---|
| Type | Metamorphic rock | Igneous rock |
| Mohs hardness | 6–7 | 6–7 |
| Luster | Granular | Granular, sparkly |
| Colors | Gray, White, Black, Pink | Pink, Gray, White, Black |
| Crystal system / structure | Coarse, banded | Coarse-grained (phaneritic) |
| Specific gravity | 2.6–2.9 | 2.63–2.75 |
| Found in | Acasta River, Canada; Outer Hebrides, Scotland | Sierra Nevada, California; Stone Mountain, Georgia |
Properties that are the same for both are grayed out.
How to identify gneiss
- Alternating light and dark bands, often wavy.
- Coarse, visible grains.
- Hard; doesn't split into sheets.
- Bands may be folded.
Structure: Coarse, banded
Full Gneiss guide →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 →More comparisons
Could you tell them apart from a blurry close-up?
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