Comparison · Igneous Rocks
Diorite vs Granite
Diorite and Granite are easy to confuse because both are igneous rocks. 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 Diorite 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: Diorite is Opaque, Granite is opaque.
- They overlap in gray, black, and white, but Diorite also comes in multicolored and Granite also comes in pink.
Diorite vs Granite properties
| Property | Diorite | Granite |
|---|---|---|
| Type | Igneous Rocks | Igneous Rocks |
| Mohs hardness | 6–7 | 6.5 |
| Luster | Vitreous to dull (granular) | vitreous |
| Streak | — | Variable; test individual minerals |
| Transparency | Opaque | opaque |
| Specific gravity | 2.8–3.0 | 2.7 |
| Crystal system | — | varies |
| Common colors | Salt-and-pepper gray, Dark gray, Black and white speckled | Pink, Gray, White, Black |
| Rarity | common | common |
| Typical specimen value | $1–$75+ | $1–$50+ |
Which is more valuable?
Typical specimens of Diorite and Granite trade in a similar range, around $10.
About Diorite
Diorite is a coarse-grained, intrusive igneous rock of intermediate composition, made mostly of plagioclase feldspar and dark hornblende or biotite, with little to no quartz. Its classic 'salt and pepper' look comes from the contrast between light gray-white feldspar and black amphibole crystals visible to the naked eye. It crystallizes slowly underground, giving it a fully crystalline, phaneritic texture.
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.
Diorite vs Granite FAQ
Is Diorite the same as Granite?
No. Both are igneous rocks, but they are distinct rock types with different hardness, streak or luster. 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 Diorite 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: Diorite is Opaque, Granite is opaque. They overlap in gray, black, and white, but Diorite also comes in multicolored and Granite also comes in pink.
Which is harder, Diorite or Granite?
They are about equally hard, both near Mohs 6–7.
Which is more valuable, Diorite or Granite?
Typical specimens of Diorite and Granite trade in a similar range, around $10.
