The stinky fluorine problem

Fluorine is a highly reactive chemical, which is why it is generally not found in its elemental form in nature. At least that was the received wisdom. New direct evidence puts to rest a debate that has lasted for two centuries regarding special fluorite mineral, the "fetid fluorite" or "antozonite"; crush the mineral and it produces a foul odor. Using, fluorine-19 nuclear magnetic (NMR) spectroscopy, researchers at the Technische Universitaet Muenchen (TUM) and the Ludwig-Maximilians-University Munich (LMU) in Germany have successfully identified natural elemental fluorine trapped within tiny inclusions found in the mineral and separated from calcium ions with which it would otherwise react.