| Crystal System |
Hexagonal |
| Chemical Comp.. |
Na3(Na,K)Al4Si4O16 |
| Color |
Colorless |
| Pleochroism |
None |
| Cleavage |
None |
| Relief |
Low |
| Birefringence |
1st Order Gray |
| 2V | --- |
| Optic Sign | Negative |
| Twinning |
None observable |