A family of minerals, related to the scapolite family, characteristically occurring in basic rocks such as nepheline syenites and sodalite syenites. A typical specimen is shown in the illustration. Cancrinite is hexagonal, a = 1.28, c = 0.52 nanometers respectively, space group P6₃, and is based on a three-dimensional linkage of (AlO₄) and (SiO₄) tetrahedra. Four-, six-, and twelve-membered aluminosilicate rings can be discerned in the structure. Large anions such as (SO₄)^2- and (CO₃)^2- occur in the hexagonal channels of the structure. The cancrinite member is white, yellow, greenish, or reddish. It has perfect prismatic cleavage, hardness is 5–6 on Mohs scale, and the specific gravity is 2.45.