Tanzanite
| Category |
| Zoisite |
| Crystal Form |
| Orthorhombic |
| Moh's Scale Hardness |
| 6.5–7.0 |
| Specific Gravity |
| 3.30–3.35 |
| Refractive Index |
| 1.69–1.70 |
| Sources |
| Tanzania near Arusha. |
Tanzanite is a variety of zoisite. It is a transparent stone with color ranging from ultramarine to sapphire blue. In artifical light, it may appear to be more violet-blue or amethyst violet.
Treatments
Tanzanite may be heat treated to intensify or improve the colour.
Caring
Tanzanite is sensitive to heat, hence avoid sudden temperature change.