Comparison · Metamorphic Rocks vs Igneous Rocks
Gneiss vs Granite
Gneiss and Granite are easy to confuse. Both sit near Mohs 6–7, 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 Gneiss and Granite
- Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Hold a thin edge to the light: Gneiss is Opaque, Granite is opaque.
- They overlap in gray, pink, black, and white, but Gneiss also comes in multicolored.
Gneiss vs Granite properties
| Property | Gneiss | Granite |
|---|---|---|
| Type | Metamorphic Rocks | Igneous Rocks |
| Mohs hardness | 6–7 | 6.5 |
| Luster | Vitreous to glimmering (mica-rich bands) | vitreous |
| Streak | — | Variable; test individual minerals |
| Transparency | Opaque | opaque |
| Specific gravity | 2.65–2.75 | 2.7 |
| Crystal system | — | varies |
| Common colors | Gray, Pink, Banded black and white, White | Pink, Gray, White, Black |
| Rarity | common | common |
| Typical specimen value | $1–$75+ | $1–$50+ |
Which is more valuable?
Typical specimens of Gneiss and Granite trade in a similar range, around $10.
About Gneiss
Gneiss is a high-grade metamorphic rock defined by coarse banding, called gneissic foliation, in which light-colored quartz and feldspar layers alternate with darker bands rich in biotite, hornblende, or garnet. It forms under intense heat and pressure deep within the crust, often from the metamorphism of granite, sedimentary rock, or a lower-grade metamorphic precursor like schist. The word gneiss derives from an old German mining term meaning roughly bright or sparkling.
About Granite
Granite is a coarse-grained igneous rock composed mainly of quartz, feldspar, and mica. It's one of the most common rocks in Earth's continental crust.
Gneiss vs Granite FAQ
Is Gneiss the same as Granite?
No. Gneiss is a metamorphic rock while Granite is a igneous rock. Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Gneiss from Granite?
Both sit near Mohs 6–7, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Hold a thin edge to the light: Gneiss is Opaque, Granite is opaque. They overlap in gray, pink, black, and white, but Gneiss also comes in multicolored.
Which is harder, Gneiss or Granite?
They are about equally hard, both near Mohs 6–7.
Which is more valuable, Gneiss or Granite?
Typical specimens of Gneiss and Granite trade in a similar range, around $10.
