Anybody use Juniper and Oak, burned down to coals, as fuel?

I use seasoned oak chunks a lot. If its a job that will take a little time I use an oak/coal combination. It stretches my coal supply and gives me a nice hot fire. If you have access to osage orange sometimes called mock orange or horse apple use that. It has one of the highest rated BTU outputs of any wood in the states.

That's just charcoal, and it works fine as fuel. Different woods have somewhat different properties as charcoal, but most will do the job. I haven't used juniper, but I can't see why it wouldn't. The Japanese have long used softwood charcoal for bladesmithing.