Comparison · Minerals
Axinite vs Dumortierite
Axinite and Dumortierite are easy to confuse because both are minerals. Dumortierite is harder (Mohs 7–8.5) than Axinite (Mohs 6.5–7), so Dumortierite will scratch Axinite and not the other way round. It scratches glass and a steel knife and cannot be scratched by a steel file. Below is a side-by-side comparison of their properties and the quick tests that separate them.
Key differences between Axinite and Dumortierite
- Dumortierite is harder (Mohs 7–8.5) than Axinite (Mohs 6.5–7), so Dumortierite will scratch Axinite and not the other way round. It scratches glass and a steel knife and cannot be scratched by a steel file.
- Hold a thin edge to the light: Axinite is Transparent to translucent, Dumortierite is Translucent to opaque.
- They overlap in brown, purple, and blue, but Axinite also comes in yellow, gray, and green and Dumortierite also comes in pink.
- Well-formed crystals give it away: Axinite is Triclinic, Dumortierite is Orthorhombic.
Axinite vs Dumortierite properties
| Property | Axinite | Dumortierite |
|---|---|---|
| Type | Minerals | Minerals |
| Mohs hardness | 6.5–7 | 7–8.5 |
| Luster | Vitreous | Vitreous, silky when fibrous |
| Streak | White | White |
| Transparency | Transparent to translucent | Translucent to opaque |
| Specific gravity | 3.27–3.35 | 3.3–3.4 |
| Crystal system | Triclinic | Orthorhombic |
| Common colors | Clove-brown, Violet-brown, Honey-yellow, Gray, Blue (rare), Green (rare) | Blue, Violet-blue, Brownish, Pink (rare) |
| Rarity | common | common |
| Typical specimen value | $2–$150+ | $2–$150+ |
Which is more valuable?
Typical specimens of Axinite and Dumortierite trade in a similar range, around $20.
About Axinite
Axinite is a group name for a series of calcium aluminum borosilicate minerals that crystallize in the triclinic system, producing distinctively thin, wedge-shaped crystals resembling an axe blade, which inspired its name. It typically forms in contact metamorphic zones where granitic intrusions meet boron-rich sedimentary or volcanic rocks. Its sharp-edged crystal habit and clove-brown to violet color make it one of the more visually distinctive borosilicate minerals collectors encounter.
About Dumortierite
Dumortierite is an aluminum borosilicate mineral crystallizing in the orthorhombic system, best known for its intense blue to violet-blue color caused by trace iron and titanium substitutions. It typically forms fibrous, needle-like crystal aggregates within metamorphic rocks rich in aluminum, such as schists and gneisses subjected to high temperature and pressure. Its deep, saturated blue color has made it a popular but often misidentified substitute for lapis lazuli and sodalite in ornamental carvings.
Axinite vs Dumortierite FAQ
Is Axinite the same as Dumortierite?
No. Both are minerals, but they are distinct species with different hardness, streak or luster. Dumortierite is harder (Mohs 7–8.5) than Axinite (Mohs 6.5–7), so Dumortierite will scratch Axinite and not the other way round. It scratches glass and a steel knife and cannot be scratched by a steel file.
How can you tell Axinite from Dumortierite?
Dumortierite is harder (Mohs 7–8.5) than Axinite (Mohs 6.5–7), so Dumortierite will scratch Axinite and not the other way round. It scratches glass and a steel knife and cannot be scratched by a steel file. Hold a thin edge to the light: Axinite is Transparent to translucent, Dumortierite is Translucent to opaque. They overlap in brown, purple, and blue, but Axinite also comes in yellow, gray, and green and Dumortierite also comes in pink.
Which is harder, Axinite or Dumortierite?
Dumortierite is harder: Mohs 7–8.5 against Mohs 6.5–7 for Axinite.
Which is more valuable, Axinite or Dumortierite?
Typical specimens of Axinite and Dumortierite trade in a similar range, around $20.
