| Mineral | Bertrandite |
|---|---|
| Formula | Be4(Si2O7)(OH)2 |
| Crystal Form | Orthorhombic/Pyramidal [mm2] |
| Cleavage | Perfect on {001}; Distinct on {100},{010},{110} |
| Color | Colorless, pale yellow |
| Density | 2.6 – 2.6 g/cm3 |
| Diaphaneity | Transparent, Translucent |
| Fracture | Brittle |
| Hardness | 6.0 - 7.0 |
| Lustre | Vitreous |
| Streak | White |
| Type Loc. | Petit-Port, Nantes, Loire-Atlantique, Pays de Loire, France |
| Dana 8 Class | 56.1.1.1 |
| Strunz Class | 8/C.07-10 |
| Mindat | mindat.org |
| WebMineral | WebMineral |
| ID | 262 |