Molecular fluorine exists in nature

Molecular fluorine, the most reactive of the chemical elements, exists in nature. So say German scientists who have discovered F₂ in the fluorite mineral anzonite, dug from a German mine.

Its natural existence has long been the subject of much debate and controversy, with many scientists believing that it simply is not possible due to its extreme reactivity. On the other hand, there have been reports of a "fluorine-like smell" emanating from samples of crushed anzonite, an ore of fluorite (calcium fluoride).

Sample of anzonite were examined by Florian Kraus from the Technical University of Munich and Jorn Schmedt auf der Gunne and Martin Mangstl from the Ludwig-Maximilians University of Munich, as they describe in an advanced article in Angewandte Chemie International Edition.

In the first instance, they "unambiguously confirmed" that the smell of crushed anzonite is the same as that of fluorine gas, but recognised that more substantial evidence was needed. They gathered this by solid-state magic-angle-spinning (MAS) NMR spectroscopy and quantitative ¹⁹F NMR experiments. Studies on several samples have yielded a maximum F₂ content of 0.46 mg/g antozonite. The occlusions of fluorine likely originate from natural radioactivity.