the race is not for the swift

I would be very surprised if it were anything but polished wood. The color variations and sheen don't look quite right for tiger's eye, and I guess it could be a very dull, subtle agate or something, but it seems unlikely to me. It's exactly the kind of wooden bracelet you get a Buddhist temples, but they were taken mainstream several years ago, though I think those were mostly plastic or stone. But it's that style, and I tend to think of wood as one of the most the classic versions.