Underwater Galleries GLO Moon Rock Cave For Your Aquarium! 100% Ceramic and Glows In The Dark. Brand new in box. Shipped within one day of payment. ****** Never before available - a ceramic rock cavethat glows in the dark! Moon Rocks are all natural and completely safe for saltwater and freshwater fish The glow comes from crystals containing tiny amounts of naturally occurring rare earth metals which we use in a special glaze. The crystals absorb ordinary light and emit a beautiful Moonbeam Blue! The more powerful the aquarium light they are under, the brighter your Moon Rock will glow. And they will glow for hours! Unlike plastic based products, these ceramic Moon Rocks are made from clay and fired to high temperatures, they will not deteriorate from uv exposure; so your Moon Rock will last for years and years! All Natural o Eco- Friendly o Green Manufactured