Gallium(III) fluoride (GaF<sub>3</sub>) is a chemical compound. It is a white solid that melts under pressure above 1000 ðC but sublimes around 950 ðC. It has the FeF<sub>3</sub> structure where the gallium atoms are 6-coordinate. GaF<sub>3</sub> can be prepared by reacting F<sub>2</sub> or HF with Ga<sub>2</sub>O<sub>3</sub> or by thermal decomposition of (NH<sub>4</sub>)<sub>3</sub>GaF<sub>6</sub>. GaF<sub>3</sub> is virtually insoluble in water. Solutions of GaF<sub>3</sub> in HF can be evaporated to form the trihydrate, GaF<sub>3</sub>÷3H<sub>2</sub>O, which on heating gives a hydrated form of GaF<sub>2</sub>(OH). Gallium(III) fluoride reacts with mineral acids to form hydrofluoric acid.