Core Glow in the Dark Stones, Approx. 135 Pebbles, Glow up to 12hrs, Every Night, Guaranteed!!! Non-toxic, inert phosphorescent material, incorporated in a plastic stone Ideal for waterscapes, landscape decoration, potted plants, lighting a pathway or driveway, gardens, crafts, aquariums, etc. Glow up to 12 hours every night! Simply expose stones to source of light to recharge! Longevity of the glow material: 20 years half-life! Aprroximately 135 stones in a 1lb bag