Grand Canyon 18-Inch Aspen Gas Logs (Logs Only - Burner Not Included). ASPEN18LOGS. Gas Fireplace Replacement Logs. Diversify the look of your fireplace with this 18-inch log set from Grand Canyon Gas Logs. Cast and painted to perfectly reflect the white Quaking Aspen, the American-made Grand Canyon Quaking Aspen Series Gas Logs are made of cement refractory material re-enforced with steel fibers and then hand hand-finished to recreate the most realistic looking log material re-enforced with steel fibers and then hand hand-finished to recreate the most realistic looking logs in the industry. Designed to be used with vented gas log systems.