Comparison · Metamorphic Rocks vs Semi-Precious Stones
Eclogite vs Garnet
Eclogite and Garnet are easy to confuse. 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 Garnet
- Both sit near Mohs 6–7.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Eclogite is Opaque, Garnet is transparent.
- They overlap in green and red, but Eclogite also comes in multicolored and Garnet also comes in orange, purple, and brown.
Eclogite vs Garnet properties
| Property | Eclogite | Garnet |
|---|---|---|
| Type | Metamorphic Rocks | Semi-Precious Stones |
| Mohs hardness | 6–7.5 | 7 |
| Luster | Vitreous (garnet and omphacite grains) | vitreous |
| Streak | — | White |
| Transparency | Opaque | transparent |
| Specific gravity | 3.3–3.6 | 3.8 |
| Crystal system | — | cubic |
| Common colors | Green (omphacite), Red (garnet), Mottled green and red | Red, Orange, Green, Purple, Brown |
| Rarity | common | common |
| Typical specimen value | $1–$75+ | $10–$3000+ |
Which is more valuable?
Garnet is usually the more valuable of the two: a typical collector specimen runs about $100 against $10 for Eclogite, and premium Garnet can reach $3000 or more.
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 Garnet
Garnet is a group of silicate minerals that share similar crystal structures. While red garnets are most common, they occur in every color except blue.
Eclogite vs Garnet FAQ
Is Eclogite the same as Garnet?
No. Eclogite is a metamorphic rock while Garnet is a semi-precious stone. 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 Garnet?
Both sit near Mohs 6–7.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Eclogite is Opaque, Garnet is transparent. They overlap in green and red, but Eclogite also comes in multicolored and Garnet also comes in orange, purple, and brown.
Which is harder, Eclogite or Garnet?
They are about equally hard, both near Mohs 6–7.5.
Which is more valuable, Eclogite or Garnet?
Garnet is usually the more valuable of the two: a typical collector specimen runs about $100 against $10 for Eclogite, and premium Garnet can reach $3000 or more.
