RocksdayGneiss vs Granulite
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 high-temperature metamorphic rock from the deep crust, often dotted with garnet.
Photo: Shannon Heinle, CC0
Key differences
- Gneiss shows clearer banding.
Side by side
| Property | Gneiss | Granulite |
|---|---|---|
| Type | Metamorphic rock | Metamorphic rock |
| Mohs hardness | 6–7 | 6–7 |
| Luster | Granular | Granular |
| Colors | Gray, White, Black, Pink | Gray, White, Pink |
| Crystal system / structure | Coarse, banded | Medium to coarse, granular |
| Specific gravity | 2.6–2.9 | 2.7–3 |
| Found in | Acasta River, Canada; Outer Hebrides, Scotland | Saxony, Germany; Southern India |
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 granulite
- Even, granular texture.
- Pale with scattered red garnets.
- Weakly banded or massive.
Structure: Medium to coarse, granular
Full Granulite guide →More comparisons
Could you tell them apart from a blurry close-up?
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