Vishnevite, or sulfatic cancrinite, is a mineral of the cancrinite group with the chemical formula (Na, Ca, K)<sub>6</sub>(Si, Al)<sub>12</sub>O<sub>24</sub>[(SO<sub>4</sub>),(CO<sub>3</sub>), Cl<sub>2</sub>]<sub>2-4</sub>÷nH<sub>2</sub>O. It has hexagonal crystals.