I thought I had mine done already. I even had thin parallel flakes covering the entire piece. While taking one of the very last finishing flakes, a crack full of gunk was revealed, about an inch down from the tip, and by the time it was cleaned up, there wasn't much left.
I wish I had taken pictures before I tried to fix it!
On the other hand, it is the first point I have made that I would have been happy to claim as mine. It was obsidian, and I did not snap it in half, so it was still a win. Best I have ever done so far.