Aquarium Rock DIY Kit (A) Aquarium Safe, All Natural Stone Iwagumi Aquascape, Cichlid Aquarium, Terrarium Plan and Design Your Own Aquascape Each Order contains 4 or more pieces of Aquarium-safe Aventurine. 10 to 11 pounds; Larger/Thicker/More substantial pieces than our 10 piece Kit. Organic, Natural Stone! No Plastic! No Resin! Each order of Rock is Natural and Unique!