Great Replacement For a Traditional Lava Rock Fill 100% NATURAL – Real naturally occurring volcanic lava stones. No fillers or colors were added. HIGH TEMPERATURE – Volcanic stones naturally resist extreme temperatures without crumbling. TUMBLED FINISH – Tumbling removes any sharp edges and gives a uniform shape. ZERO MAINTENANCE – Will not discolor, fade, or crumble. Rolled Lava Stones Gray in color Size: 2.5″- 4.5″  A simple no-frills look that appeals to many. These rolled lava stones look like true smooth-washed stones you would find on the beach.  1/2 Cubic Foot Bag (about 50 lbs) will cover a 18″ to 24″ ring.