The American Fire Glass Medium Lava Stones sets are your solution to a more ecofriendly fire media. Crafted and smoothed down from hardened volcanic lava, these stones withstand more and gives more heat without ever breaking. What makes them eco-friendly is that they don't produce any soot nor emit any toxic fumes. This means you can spend more time by the fire without any worries. Each set comes with several 1"-2" lava stones. When used correctly, there is hardly any upkeep and the stones will last for a lifetime. American Fire Glass is a pioneer in the hearth products industry. We take pride in delivering the highest quality of products to our customers. It's why we have a Lifetime Warranty on many of our products, including our Lava Stones.