Gallium(III) fluoride (GaF3) is a chemical compound. It is a white solid that melts under pressure above 1000 °C but sublimes around 950 °C. It has the FeF3 structure where the gallium atoms are 6-coordinate. GaF3 can be prepared by reacting F2 or HF with Ga2O3 or by thermal decomposition of (NH4)3GaF6.[1] GaF3 is virtually insoluble in water.[1] Solutions of GaF3 in HF can be evaporated to form the trihydrate, GaF3·3H2O, which on heating gives a hydrated form of GaF2(OH).[1] Gallium(III) fluoride reacts with mineral acids to form hydrofluoric acid.