1" Glow in The Dark Rocks- >450pcs (2.4LB) Glowing Acrylic Stones for Outdoor Garden Landscaping Pathway - Glowing Luminous Rocks for Indoor Fish Tank Aquarium Planter Vase Filler - Blue. 【Blue Glow in the Dark Rocks 】- Our glowing rocks absorb and energy from natural sunlight and other light sources, so they will continue to glow for up to 8 hours in darkness.
eBay