RocksdayEclogite vs Zoisite
How to tell them apart
A striking red-and-green rock of garnet and green pyroxene formed at great depth.
Photo: No machine-readable author provided. Woudloper assumed (based on copyright claims)., Public domain
A calcium aluminum silicate best known as green rock studded with red ruby crystals.
Photo: Robert M. Lavinsky, CC BY-SA 3.0
Quick tests
- Texture: Eclogite is a rock — a mix of grains or minerals; Zoisite is a single mineral.
Key differences
- Ruby in zoisite has pink-red ruby, not round garnets.
Side by side
| Property | Eclogite | Zoisite |
|---|---|---|
| Type | Metamorphic rock | Mineral |
| Mohs hardness | 6–7 | 6–7 |
| Luster | Vitreous | Vitreous |
| Streak | — | White |
| Colors | Green, Red | Green, Pink, Gray |
| Crystal system / structure | Coarse, garnet and omphacite | Orthorhombic |
| Specific gravity | 3.4–3.6 | 3.15–3.38 |
| Formula | — | Ca₂Al₃(SiO₄)(Si₂O₇)O(OH) |
| Found in | Western Norway; Western Alps, Italy | Longido, Tanzania; Norway |
Properties that are the same for both are grayed out.
How to identify eclogite
- Red garnets in a green matrix.
- Exceptionally heavy.
- Glassy, coarse crystals.
Structure: Coarse, garnet and omphacite
Full Eclogite guide →How to identify zoisite
- Green massive stone, often with red ruby and black hornblende.
- Pink variety (thulite) is opaque.
- Hardness about 6.5.
Crystal system: Orthorhombic
Full Zoisite guide →More comparisons
Could you tell them apart from a blurry close-up?
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