... and blue 3. high intensity, smooth surface,more cleansing Luminous Ceramic Pebbles 1.Material: ceramics and photoluminescent pigment.2.Afterglow time ... resistant, resistant to sunlight, aging resistance,long service life.Luminous cobblestone is a man-made glowing stone, based on ... 4.5cmAverage Weight8g, 20g, 28gShapePebble, Cobble, triangleWater ResistantYesUV ResistantYes Luminous Ceramic Pebbles