Luminescence principle: The stones absorb and store energy after being exposed to visible light, such as sunlight and other light, for more than half an hour. They can glow naturally in the dark for 30 minutes to 2 hours. Illuminate them again if they are not bright enough. The product repeatedly absorbs light. Quantity: You will receive 300 luminous stones weighing 120 grams per order. Uses: DIY decorations for vases, aquariums, fish tank decorations, gardening, pools, ponds, bar decorations, homes, parks, bird baths, water features, landscapes, planters, potted plants, patios, lawns, garden aquariums, and craft decorations. Safe and non-toxic: These sparkling stones are made of synthetic resin and are non-toxic and non-radioactive. They are safe for humans and pets. Luminous stones are not harmful to humans. Beautiful appearance: The stone is diamond-shaped and has a smooth surface. The darker the environment and the longer the stone is exposed to light, the stronger the visible light will be. Do not stack the stones on top of each other when applying. Show more