| Thermal properties | Standard value |
| Transformation point | 1280°c |
| Softening point | 1780°c |
| Annealing point | 1250°c |
| Specific heat | 670J/kg.°c |
| Thermal conductivity | 1.4W/m.°c |
| Index of refraction | 1.4585 |
| Thermal processing temperature | 1750 - 2050°c |
| Short-term use temperature | 1300°c |
| Long-term use temperature | 1100°c |