WE have already outlined 1 the results of an X-ray examination of thin calcium fluoride films, evaporated on polished glass surfaces. The powder X-ray camera used was of the Seeman–Bohlin ...

Fluorine's name derives from fluorspar — or fluorite, CaF 2 (pictured) — which in earlier times was used as a flux to facilitate smelting. As early as the seventeenth century, fluorspar was ...