The Penn-Plax Crystal Cluster Aquarium Ornament is an eye-catching addition to your aquarium， and it’s sure to turn heads. This decoration provides visual interest for both you and your fishy friends. The crystal cluster is a formation of individual， single terminated crystal points. Amethyst， the stone of sobriety， adds beauty to your tank and sparkles brightly underwater. This clyster is perfect for the mineral collector. It’s crafted of durable and nontoxic polyresin and is suitable for both freshwater and saltwater tanks.