The Outdoor GreatRoom Company Lava Rock gives your fire feature a traditional and more realistic look. Lava rocks will look even better with alog set. Black lava rocks and tumbled lava rocks are available. Your burner comes with standard media, but in case you want your fire feature to have a more traditional look, lava rocks are a great addition. Black lava rocks are sold in 20-lb bags. Tumbled Lava Rocks vary in size, from .75"-1.5" and are sold in 6-lb bags. Initially, these may appear darker when you first open the package. After it is burned and the extra moisture is released they will turn more grey. Enhance the look of your fire pit even further by adding black or tumbled lava rocks!