Line a pathway bordering a flower bed or decorate a garden aquarium with these unique pebbles. The glow lasts about two to three hours after exposure to full sunlight 100pcs/lot Size: 2-3cm/0.78-1.18inch Color: mix/white/green/yellow/rose red/blue Material: Photoluminescent pigment + resin Package 1. Q: Is the luminous stone not glowing invalid? A: The luminous stone is a light-storing product. The principle is that it can emit light by absorbing the light source. Each time the light is emitted is 8-12 hours, during which the first 1-2 hours are the high light period and continue to glow. The received product did not emit light because there was no absorption light source during logistics. As long as you have sunlight or light for a period of time, you can glow again. 2. Q: Why do I have a day of sunshine during the day and it is still not lit at night? A: Because the principle of luminous is to absorb light and emit light, which means it begins to glow in the process of storing light. If the light is absorbed during the day but after one twilight hour, the luminous period of the luminous light is over, so you can only see it slightly. Dim light but when you turn on the lights, you can see very clearly. 3. Q: What is the brightest color of the luminous stone? A: The luminous stones are luminous in white color like green yellow green bright blue and green. Other colors are colored with yellow-green powder plus color powder. The toner will cover the luster of the luminous powder. After being exposed to strong daylight for 3 hours, these pebbles can be lit in 1-2 hours in the dark. Note: Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you.