I try to sharp a shell for shaving but no function , I think the story about in the pass time the man shaving with a shell is no true , I tried and tried and no work .
I seem to recall reading that shells were typically used in a depilatory fashion, meaning you'd use a pair of them like tweezers and actually pluck hairs rather than shave them.
Under extreme magnification, obsidian blades show a smoother edge than stainless steel razors do. The steel edge appears to have pits, porosity, and other discontinuities, where the obsidian edge appears smooth and even with very few discontinuities.