KF-LiF equilibrium phase diagram. Phases at equilibrium for the chemical system KF-LiF are shown as a function of chemical composition (mole percent LiF) and temperature at atmospheric pressure (1 bar). The orange area indicates temperatures and compositions for which a single phase, molten salt (magma), is present at equilibrium. The liquid only region is bounded by saturation curves: saturation with a solid KF phase on the left and saturation with a solid LiF phase on the right. These solids do not occur in rocks, so they do not have mineral names. Saturation curves like these are also called liquidus curves. The KF and LiF saturation curves meet at a single point called a eutectic point, which marks the lowest temperature that liquid can exisit in this system. Areas that have the horizontal line pattern indicate temperatures and compositions for which two phases are in equilibrium. This diagram is based on the collection of alkali halide phase diagrams by Sangster and Pelton (1987).