Cryolite is a white natural fluoride of aluminum and sodium. It's nearly invisible in water, in powdered form, and is used chiefly in the electric recovery of aluminum. Cryolite is found mainly in Ivittuut, Greenland, and in small deposits in Spain and Colorado, United States. It once had a great deposit in Ivittuut, Greenland, but the mine ran out in 1987. The town is now abandoned.