Other phosphorescent materials suitable for this invention are alkaline earth aluminates of the formula MO.Al2O3.B2O3:R wherein M is a combination of more than one alkaline earth metal (strontium, calcium or barium or combinations thereof) and R is a combination of Eu2+ activator, and at least one trivalent rare earth material co-activator, (e.g. lanthanum, cerium, praseodymium, neodymium, samariu