"Obsidian (volcanic glass) scalpels have been considered as an alternative to steel scalpels due to the narrowness of the cutting edge. When incisions made with

"Obsidian (volcanic glass) scalpels have been considered as an alternative to steel scalpels due to the narrowness of the cutting edge. When incisions made with each type of scalpel are viewed microscopically, one made with a steel scalpel will reveal tearing of individual cells, yet obsidian cuts between individual cells." That's pretty incredible.