Newstone's Natural Zeolite Rock - Chunks of Large Natural Zeolite Rock, Mined From Japan (1.1lbs / 500grams) - Great for Odor Removal in Room, Use in Aquarium to Remove Ammonium Keeps air fresh in closets, basements, vehicles, pet areas, and smoking areas 100% Natural Stone from Japan. Odorless natural materials from earth Non-toxic, environmentally safe. This is a Natural Mineral Stone , so size may vary from 2cm to 4cm or even larger. Please understand that our products are genuine natural stones, so sizes of each stone will vary in sizes. Material name: Zeolite ( Clinoptilolite). High purity of clinoptilolite. Cation exchange capacity (CEC) is excellent level among the world, boasting 170cmolc / kg. Natural Zeolites can be used in some areas of industry including feed additive / soil conditioner, waste water treatment media, cat litter, pool filtration media, aquacultural uses, aquarium filtration media, radioactive water treatment, fillers. Gas purification and seperation, and Lightweight Construction Materials.