Strontium Aluminate with Europium as the activator. This stuff beats the tar out of any Zinc Sulfide which is what you have been use to. It glows brightly for hours and hours. You can use the powder by mixing with paints, glue, epoxy, plastics you name it! Glows for over 100 Hours! You have to see the colors to believe it! Perfect for Star Murals! Non-Toxic! Harmless! Non-Radioactive Buy some and see for yourself how amazing the powder is.