About 10 years ago I acquired 3 black walnut logs from a homeowner. I took the logs to a local guy with a wood mizer and milled and kiln dried the lumber. It's been stacked in my garage for the past 5 years. I started pulling boards from the stack this weekend and have noticed that the boards are sparingly covered in what looks to be a glitter like substance. It's hard to spot unless you look close and move back and forth until the light reflects off a piece. I vacuumed a board and it came right off. I took my hand plane and after several swipes the walnut almost looks like it has microscopic glass crystals in it. I've never seen this before. Is this natural or doe anyone have any idea what this could be? The guy that dried the lumber was just getting started, I'm not convinced he knew everything he was doing, is it possible something was added during to the kiln during the drying process?