... : Strontium Aluminate based.Appearance: Milky crystal powder.Average particle size range: 20~30um.Luminous color: Blue-purple.Free of dangerous, toxic, heavy ... the dark powder, photoluminescent pigment, photoluminescent powder, photo luminescent pigment, photo luminescent powder, luminous pigment, luminous powder, luminescent pigment, luminescent powder, glowing pigment, glowing powder, night ...