| |
 |
Tourmaline Gemstones
- Crystal system: Trigonal
- Chemical composition: Borosilicate complex
- Color: Green
- Hardness: 7.0 - 7.5
- Specific gravity: 3.06
- Refractive index: 1.62 - 1.64
- Dispersion: 0.017
- Pleochroism: pale green, dark green
- Enhancements: Some very dark green and dark blue green tourmalines are heated to lighten their colors. The treatment is permanent and only occasionally performed.
| Displaying 61 to 62 (of 62 products) |
Result Pages: 3 |
|
|
|
