Black locust has a very high BTU rating. I've burned just a little of it, from some old dead branches. The guy who gave it to me said its fine to burn in a stove, but because its so dense, it pops and explodes if there's any moisture in the firewood, and could be a hazard in an open fire situation. I don't know if that is accurate.

Honey locust is only slightly less dense, excellent for firewood.

Both can be very hard to split, due to their density.

But don't try to START a fire using either of them. Get your fire well started, then add your locust logs.

Sue