Is this mold? It's in streaks through-out the wood I cut. On the outside it looks greenish, same as the inside depending on how the light hits it then it looks black. I've seen this several times, don't know what it is. I think the wood is either old ash or elm, it has been dead a few years. I picked it up this summer, it's not quite punky but is pretty dry. It borders soft/punky. I hate to throw it away/burn it, it has some nice markings through-out.

