Hexagonal, Nonmetal, Rare earth, Photoluminescence spectra

• Al-Ba-Eu-Mg-O
• F-Gd-Ho-Na-Yb
• Ba-Cl-Eu-O-P
• Ca-Eu-F-O-P-Sr
• Ca-Eu-F-O-P
• nonmetal
• rare earth
• lanthanoid
• luminescent
• chalcogen