Yes, all "fire glass" can be used with any fire. If you use it with wood logs it would get dirty and sooty but it would still be fine. The point of using special "fire glass" is that it will not melt or degrade at high temperatures. It's perfectly safe to use with any fire and a natural gas fireplace would be fine as long as you read the information that comes with your particular fireplace to insure safety. The glass it's self is 100% safe to use indoors.
2 years, 3 months ago