The chemical and physical properties of benitoite and its associated minerals have been described by Louderback and Blasdale, and the following notes are taken from their description. The chemical analyses show it to be an acid barium titano-silicate corresponding to the formula BaTiSi₃O₉ . Benitoite is insoluble in ordinary acids, but is attacked by hydrofluoric acid and dissolves in fused sodium carbonate. Alone, it fuses quietly to a transparent glass at about 3. The color of benitoite is not affected by heating the stone to redness and allowing to cool. The hardness is greater than orthoclase and less than peridot, or about 6 to 6 1/2, and the specific gravity is 3.64 to 3.67.

Benitoite crystallizes in the trigonal division of the hexagonal system. The common forms observed are the base c(0001), trigonal prisms m(1010), and n(0110), and the trigonal pyramids p(1011) and π(0111). Other forms are rather rare and of small importance. Of these faces the pyramid π generally has the largest development. This gives the crystal a triangular aspect with the corners truncated by smaller planes. The prism faces are narrow, though generally present. Many of the crystals are naturally etched on one or more sets of faces. Such faces are a little dulled or slightly pitted. Benitoite has an imperfect pyramidal cleavage and a conchoidal fracture.