The oxygen atom in their chemistries might require their classification in the Oxides Class of minerals except that their 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 , botallackite , laurionite , paralaurionite , mendipite , fiedlerite , pinchite , penfieldite , yedlinite , atacamite , koenenite , diaboleite , 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 indigo blue. Luster is vitreous to pearly.
Crystals are usually translucent to transparent.
It is often intergrown with boleite in parallel growth. Crystals can be pseudocubic. Cleavage is perfect. Fracture is uneven. Streak is light green to blue.