Comparison · Igneous Rocks
Granite vs Tonalite
Granite and Tonalite are easy to confuse because both are igneous rocks. Both sit near Mohs 6.5, 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 Granite and Tonalite
- Both sit near Mohs 6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
- Streak color differs: Granite leaves a variable; test individual minerals streak on unglazed porcelain, Tonalite leaves white to light gray.
- Luster is different: Granite is vitreous while Tonalite is dull.
- They overlap in gray, white, and black, but Granite also comes in pink and Tonalite also comes in green.
Granite vs Tonalite properties
| Property | Granite | Tonalite |
|---|---|---|
| Type | Igneous Rocks | Igneous Rocks |
| Mohs hardness | 6.5 | 6 |
| Luster | vitreous | dull |
| Streak | Variable; test individual minerals | White to light gray |
| Transparency | opaque | opaque |
| Specific gravity | 2.7 | 2.75 |
| Crystal system | varies | varies |
| Common colors | Pink, Gray, White, Black | White, Gray, Black, Salt and pepper, Greenish gray |
| Rarity | common | common |
| Typical specimen value | $1–$50+ | $1–$75+ |
Which is more valuable?
Typical specimens of Granite and Tonalite trade in a similar range, around $10.
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.
About Tonalite
Tonalite is a coarse-grained intrusive igneous rock rich in plagioclase and quartz, with less alkali feldspar than granite. It often looks gray, white, and black speckled.
Granite vs Tonalite FAQ
Is Granite the same as Tonalite?
No. Both are igneous rocks, but they are distinct rock types with different hardness, streak or luster. Both sit near Mohs 6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead.
How can you tell Granite from Tonalite?
Both sit near Mohs 6.5, so a scratch test alone will not separate them. Lean on luster, streak and heft instead. Streak color differs: Granite leaves a variable; test individual minerals streak on unglazed porcelain, Tonalite leaves white to light gray. Luster is different: Granite is vitreous while Tonalite is dull.
Which is harder, Granite or Tonalite?
Granite is harder: Mohs 6.5 against Mohs 6 for Tonalite.
Which is more valuable, Granite or Tonalite?
Typical specimens of Granite and Tonalite trade in a similar range, around $10.
