Acrylic Clear Ice Rock Cubes 300g/Bag - Great Idea for Vase Fillers and Table Decorating Commonly used for filler in vases for centerpieces or home decor. Use for aquarium decor. These will sink to the bottom of the tank. Spread these on the table for table scatter at your next event or dinner gathering. Each gem measures approximately 1", 2g Item is completely transparent. Light will shine through them. Made of acrylic - Acrylic is a clear high grade plastic.