This stone has become famous the last couple of weeks, if it's the one from ebay. It doesn't look like a Charnley. Those flake chips from the description sounds like Novaculite, but if you think they look like a slate type, I don't know. I wouldn't say it's definitely not a Charnley, but whatever it is, it's an interesting specimen. It kind of looks like the unknown stones that again look like Llyn Idwals or TOSs but we can't be sure what they are. Good luck.