Calcium Fluoride (CaF₂)

Calcium Fluoride is a cubic single crystal which has a good transmittance from 170nm to 8000nm. The crystal is resistance to water, and organic chemicals and many acids, including HF. But it will slowly dissolve in nitric acid and it is sensitive to thermal shock. It can be machined with standard diamond tools and have a good polishing quality using either aluminum oxide or diamond based polishing papers. Calcium Fluoride, like Magnesium Fluoride, is a good material for use with excimer lasers. It can be manufactured into windows, lenses and prisms.