Well said, Hikermor. Cage Baker included uded a riff in one of her books involving some elder tribal members complaining about the younger folk demanding obsidian tools when the old-fashioned chipped flint was equally serviceable. Back in the days of radial keratotomy surgery for vision correction, the ophthalmologists were using dies bladed with obsidian. This would be in the eighth decade of the 20th century AIRC.