German researchers have succeeded in proving the presence of elemental fluorine in a mineral called antozonite. The most reactive chemical element, fluorine, has been claimed not to occur in nature. First direct evidence from in situ NMR spectroscopy now proves that elemental fluorine indeed occurs in nature as an occlusion in antozonite (Didier Descouens) Fluorine is the most reactive of all chemical elements and calls for extremely careful handling....