Yttrium aluminium garnet (YAG, Y 3 Al 5 O 12 ) is a synthetic crystalline material of the garnet group. It is also one of three phases of the yttria-aluminum composite, the other two being yttrium aluminum monoclinic (YAM) and yttrium aluminum perovskite (YAP). YAG is commonly used as a host material in various solid-state lasers. Rare earth elements such as neodymium and erbium can be doped into YAG as active laser ions, yielding and lasers, respectively. Cerium-doped YAG (YAG:Ce) is used as a phosphor in cathode ray tubes and white light-emitting diodes, and as a scintillator.