Comparison · Metamorphic Rocks
Eclogite vs Unakite
Eclogite and Unakite are easy to confuse because both are metamorphic rocks. Both sit near Mohs 6–7.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Eclogite and Unakite
- Both sit near Mohs 6–7.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Eclogite feels noticeably heavier for its size (specific gravity 3.3–3.6 versus 2.9 for Unakite).
- Hold a thin edge to the light: Eclogite is Opaque, Unakite is opaque.
- They overlap in green and multicolored, but Eclogite also comes in red and Unakite also comes in pink.
Eclogite vs Unakite properties
| Property | Eclogite | Unakite |
|---|---|---|
| Type | Metamorphic Rocks | Metamorphic Rocks |
| Mohs hardness | 6–7.5 | 6.5 |
| Luster | Vitreous (garnet and omphacite grains) | vitreous |
| Streak | — | Variable; test individual minerals |
| Transparency | Opaque | opaque |
| Specific gravity | 3.3–3.6 | 2.9 |
| Crystal system | — | varies |
| Common colors | Green (omphacite), Red (garnet), Mottled green and red | Pink and Green mottled, Salmon, Olive Green |
| Rarity | common | common |
| Typical specimen value | $1–$75+ | $2–$50+ |
Which is more valuable?
Typical specimens of Eclogite and Unakite trade in a similar range, around $10.
About Eclogite
Eclogite is a dense, coarse-grained metamorphic rock composed primarily of red garnet and green sodium-rich pyroxene called omphacite, formed only under the extreme pressures found deep within the crust or upper mantle. Its striking red-and-green coloration makes it one of the most visually distinctive metamorphic rocks, and its mineralogy records some of the highest-pressure conditions preserved in rocks that return to Earth's surface. Eclogite forms from basaltic protoliths subjected to pressures typically exceeding those of ordinary regional metamorphism.
About Unakite
Unakite is a metamorphosed granite composed of pink orthoclase feldspar, green epidote, and quartz. Named after the Unaka Mountains of Tennessee.
Eclogite vs Unakite FAQ
Is Eclogite the same as Unakite?
No. Both are metamorphic rocks, but they are distinct rock types with different hardness, streak or luster. Both sit near Mohs 6–7.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Eclogite from Unakite?
Both sit near Mohs 6–7.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Eclogite feels noticeably heavier for its size (specific gravity 3.3–3.6 versus 2.9 for Unakite). Hold a thin edge to the light: Eclogite is Opaque, Unakite is opaque.
Which is harder, Eclogite or Unakite?
They are about equally hard, both near Mohs 6–7.5.
Which is more valuable, Eclogite or Unakite?
Typical specimens of Eclogite and Unakite trade in a similar range, around $10.
