Diaboleite is only known from Mendip Hills, Somerset, England and a couple of localities in Arizona . These three minerals and others with similar chemistries belong to a division in the Halides Class called the Oxyhalides and Hydroxyhalides . The oxygen atom in the formula might require classification in the Oxides Class of minerals except that the structures are more tied to the halide elements and the oxygens and hydroxides are kind of superfluous to the overall structure. Some other members of the Oxyhalides and Hydroxyhalides include bideauxite , chloroxiphite , kelyanite , blixite , botallackite , laurionite , paralaurionite , mendipite , fiedlerite , pinchite , penfieldite , yedlinite , atacamite , koenenite , cumengite , zirklerite and paratacamite . Of these, only atacamite and boleite are common enough to be seen at rock shows and in rock shops with regularity.
Color is sky blue to dark blue.
Luster is adamantine. Crystals are usually translucent to transparent. Cleavage is perfect. Fracture is conchoidal. Streak is blue.