Here's my take. It resembles in some ways hickory that I have worked with before, that had some sort of disease which turned the wood a different color and made it softer because it was essentially dead wood. The tree itself was still alive when I cut it, because it had green leaves. But the wood is not the same. It was softer, worked different, and was not quite as strong. This may be what you have.
Have you worked hickory before, so as to know what it should be like? Does this wood feel softer (can your fingernail put a significant groove in it)? If you scrape it, does it scrape very easily, losing larger flakes at a time?
~~Papa Matt
