Comparison · Metamorphic Rocks
Marble vs Skarn
Marble and Skarn are easy to confuse because both are metamorphic rocks. Skarn is harder (Mohs 5.5) than Marble (Mohs 3.5), so Skarn will scratch Marble and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Marble and Skarn
- Skarn is harder (Mohs 5.5) than Marble (Mohs 3.5), so Skarn will scratch Marble and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
- Streak color differs: Marble leaves a white streak on unglazed porcelain, Skarn leaves variable by mineral content.
- Luster is different: Marble is vitreous while Skarn is dull.
- Hold a thin edge to the light: Marble is translucent, Skarn is opaque.
- They overlap in white, gray, green, and black, but Marble also comes in pink and Skarn also comes in brown and red.
Marble vs Skarn properties
| Property | Marble | Skarn |
|---|---|---|
| Type | Metamorphic Rocks | Metamorphic Rocks |
| Mohs hardness | 3.5 | 5.5 |
| Luster | vitreous | dull |
| Streak | White | Variable by mineral content |
| Transparency | translucent | opaque |
| Specific gravity | 2.7 | 3.1 |
| Crystal system | varies | varies |
| Common colors | White, Gray, Pink, Green, Black | Green, Brown, White, Gray, Red, Black |
| Rarity | common | uncommon |
| Typical specimen value | $5–$500+ | $2–$150+ |
Which is more valuable?
Marble is usually the more valuable of the two: a typical collector specimen runs about $50 against $20 for Skarn, and premium Marble can reach $500 or more.
About Marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals. It has been used for sculpture and architecture since ancient times.
About Skarn
Skarn is a calc-silicate metamorphic rock formed where hot intrusive fluids alter carbonate rocks. It can be green, brown, white, red, or mixed and may contain garnet, pyroxene, epidote, or ore minerals.
Marble vs Skarn FAQ
Is Marble the same as Skarn?
No. Both are metamorphic rocks, but they are distinct rock types with different hardness, streak or luster. Skarn is harder (Mohs 5.5) than Marble (Mohs 3.5), so Skarn will scratch Marble and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not.
How can you tell Marble from Skarn?
Skarn is harder (Mohs 5.5) than Marble (Mohs 3.5), so Skarn will scratch Marble and not the other way round. A steel knife blade (Mohs 5.5) scratches it; a copper coin does not. Streak color differs: Marble leaves a white streak on unglazed porcelain, Skarn leaves variable by mineral content. Luster is different: Marble is vitreous while Skarn is dull.
Which is harder, Marble or Skarn?
Skarn is harder: Mohs 5.5 against Mohs 3.5 for Marble.
Which is more valuable, Marble or Skarn?
Marble is usually the more valuable of the two: a typical collector specimen runs about $50 against $20 for Skarn, and premium Marble can reach $500 or more.
