Featherock landscaping boulders are made of lightweight natural pumice. They can be used in virtually any landscaping project! They are available in sizes from 6" up to 7' and come in 4 stunning colors of Silver-Grey, Charcoal, Brindle, and Buckskin. Pumice is easily customized and can be sculpted into custom water features and even planters. It's lightweight nature allows it to be used in rooftop garden applications, decks, interiorscaping, and more.