Glow in the dark rocks and stones from Hangzhou Yeming is made from high quality glow powders and glass/synthetic resins,they are non-toxic and eco-friendly.After simply exposing them to direct sunlight or regular indoor lighting,they can glow all night long.Our large glow rocks are tumbled and have no sharp edges,the small glow rocks are more jagged and work well as aggregate. It can be widely used for landscaping,driveway,fish ponds,swimming pools, lawns, backyards, and much more. Please don't waste your money on the glow in the dark plastic pebbles,because they will not glow longer than an hour.