Crystal symmetry: 4/mm
Density: 7,19 g/cm^3
Optical spectral range: 0,38 - 28 mkm
Elastic constants 
: 10^11 dyn/cm^2 or 10^10 Pa)
| 1.8925 | 1.7192 | 1.563 | 0 | 0 | 0 |
| 1.7192 | 1.8925 | 1.563 | 0 | 0 | 0 |
| 1.563 | 1.563 | 8.037 | 0 | 0 | 0 |
| 0 | 0 | 0 | 0.8456 | 0 | 0 |
| 0 | 0 | 0 | 0 | 0.8456 | 0 |
| 0 | 0 | 0 | 0 | 0 | 1.225 |
Photolastic constants 
:
| 0.551 | 0.44 | 0.256 | 0 | 0 | 0 |
| 0.44 | 0.551 | 0.256 | 0 | 0 | 0 |
| 0.137 | 0.137 | 0.01 | 0 | 0 | 0 |
| 0 | 0 | 0 | -- | 0 | 0 |
| 0 | 0 | 0 | 0 | -- | 0 |
| 0 | 0 | 0 | 0 | 0 | 0.047 |
Refraction indices:
The values for refraction coefficients for the given optical wavelengths.
| wavelength, mkm |  |  |
|---|
| 0.6328 | 1.96 | 2.62 |
|---|
Sound velocity:
| direction | polarization | v (10^5 cm/s) |
|---|
| [100] | [100] | 1.622 |
| [101] | [101] | 2.641 |
| [100] | [100] | 2.054 |
| [001] | [001] | 3.343 |
| [001] | [010] | 1.084 |
| [100] | [010] | 1.305 |
| [110] | [1-10] | 0.347 |
| [101] | [101] | 1.132 |
| [101] | [010] | 1.206 |
Calomel slowness surfaces in important planes
Acousto-optic figure of merit:
| sound dir. | sound pol. | light dir. | light pol. | M (10^-18 s^3/g) |
|---|
| [100] | [100], L | -- | [100] | 506 |
| [100] | [100], L | -- | [010] | 340 |
| [110] | [110] | -- | [110] | 273 |
| [110] | [110] | -- | [1-10] | 183 |
| [110] | [1-10] | -- | arb. | 640 |
| [001] | [001], L | -- | [001] | 0.17 |
