 The ytterbium ( III ) ion absorbs light in the near infrared range of wavelengths , but not in visible light , so the mineral ytterbia , <unk> , is white in color and the salts of ytterbium are also colorless . Ytterbium dissolves readily in dilute sulfuric acid to form solutions that contain the colorless Yb ( III ) ions , which exist as <unk> complexes : 
