Carobbiite, chemical formula KF (potassium fluoride), is a rare, soft (Mohs 2 - 2.5), colourless 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. References Potassium minerals Fluorine minerals Cubic minerals Minerals in space group 225 Rocksalt group