Carobbiite, chemical formula KF (potassium fluoride), is a rare, soft (Mohs 2 - 2.5), colorless cubic mineral. It is found at Monte Somma, Somma-Vesuvius Complex, Province of Naples, Campania, Italy. It was discovered in 1956 by Italian geologist Guido Carobbi (1900–1983). It has also been reported from Hokkaido, Japan.
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Carobbiite Wikipedia(Text) CC BY-SA