Natural Stone; a high-class stone completely natural from the mountains. USI Walkways are natural stone carefully crafted after being exploded from the mountains sourced globally. The value these stones carry will last a lifetime, and give your property a bold and compelling look! While manufactured stones are made from synthetic materials, natural stone is straight from the earth! For a reference, compare 24 karat gold to gold plated jewelry; which one would you go for? USI has all types of Natural Stone. Check out our collection!