| Mineral | Dumortierite |
|---|---|
| Formula | Al6.5-7(BO3)(SiO4)3(O,OH)3 |
| Crystal Form | Orthorhombic/Dipyramidal [2/m 2/m 2/m] |
| Cleavage | [100] Good, [110] Indistinct |
| Color | Blue, Brown, Violet, Greenish blue, Pink |
| Density | 3.3 – 3.4 g/cm3 |
| Diaphaneity | Transparent to Translucent |
| Fracture | Fibrous |
| Hardness | 8.5 |
| Lustre | Vitreous |
| Streak | White |
| Dana 8 Class | 54.1.2.1 |
| Strunz Class | VIII/B.31-20 |
| Mindat | mindat.org |
| WebMineral | WebMineral |
| ID | 106 |