Tumbled Lava Pebbles with Lava filler

Tumbled Lava pebbles have a natural look, but just like Lava might pop if the fire is on and the pebbles are moist.  The Tumbled Lava Pebbles (Rolled Lava) on top, in mixed sizes, small, medium, and large, filler underneath is Lava rock. 

Shown here in a Simplicity Edge in Mahogany Acid finish.