CaF2
Density：3.18g/cm^3
Transmission：＞90%@0.13-10μm
Homogeneity：＜5×10^-6
Cleavage plane：<111>
| Size | Range of sizes | Perpendicular | Surface Quality S/D | Flatness | Angle tolerance | Parallelism | CA |
| Small | 5×5-10×10mm | 1′ | 20/10-60/40 | λ/4-λ/10 | 2″-60″ | 2″-3′ | 90% |
| Medium | 20×20-50×50mm | 1′ | 20/10-60/40 | λ/4-λ/10 | 2″-60″ | 2″-3′ | 90% |
| Large | 60×60-100×100mm | 1′ | 40/20-80/50 | λ/4-λ/10 | 2″-60″ | 2″-3′ | 90% |
