Are fluorite lenses prone to cracking?
Fluorite glass can crack if subject to extreme rapid temporature changes, but it is relatively rare. I don’t know where in the lens the fluroite elements are located. If they are exposed to the air and you take them from a very warn environment to a very cold environment, they might crack. Fluorite lenses are also used in high end apochromatic telescopes, for example see the Televue Vixen or similar.
