Benitoite
| Colour | Blue |
|---|---|
| Mohs hardness | 6–6.5 |
| Lustre | Vitreous |
| Streak | White |
| Crystal system | Hexagonal |
| Transparency | Transparent to translucent |
| Cleavage | [101] poor |
| Fracture | Conchoidal |
| Chemical formula | BaTiSi 3 O 9 |
| Specific gravity | 3.65 |
What is Benitoite?
Benitoite is a rare, blue, barium titanium cyclosilicate mineral, found in hydrothermally altered serpentinite. It forms in low-temperature, high-pressure environments typical of subduction zones at convergent plate boundaries. Benitoite fluoresces under short-wave ultraviolet light, appearing bright blue to bluish white in color. The more rarely seen clear to white benitoite crystals fluoresce red under long-wave UV light.
How to identify Benitoite
- Lustre: Vitreous.
- Hardness: Mohs 6–6.5 — about as hard as a steel knife.
- Streak: White.
- Habit: Hexagonal crystal system.
Benitoite in different forms
Frequently asked questions
How hard is Benitoite?
Benitoite is Mohs 6–6.5 on the hardness scale.
What colour is Benitoite?
Benitoite is typically blue (Blue, colorless).