( CNN ) Ever had a headache so big , you felt like drilling a hole in your head to let the pain out ? In Neolithic times trepanation -- or drilling a hole into the skull -- was thought to be a cure for everything from epilepsy to migraines . It could even have been a form of emergency surgery for battle wounds . But while there is still conjecture about the real reasons behind the mysterious procedure , what is known is that the implement often used to carry out the primitive surgery was made from one of the sharpest substances found in nature -- obsidian . Obsidian -- a type of volcanic glass -- can produce cutting edges many times finer than even the best steel scalpels . At 30 angstroms -- a unit of measurement equal to one hundred millionth of a centimeter -- an obsidian scalpel can rival diamond in the fineness of its edge . When you consider that most household razor blades are 300-600 angstroms , obsidian can still cut it with the sharpest materials nano-technology can produce . Even today , a small number of surgeons are using an ancient technology to carry out fine incisions that they say heal with minimal scarring . Dr. Lee Green , professor and chair of the Department of Family Medicine at the University of Alberta , says he routinely uses obsidian blades . `` The biggest advantage with obsidian is that it is the sharpest edge there is , it causes very little trauma to tissue , it heals faster and more importantly it heals with less scarring , '' he said . `` It makes for the best cosmetic outcome . '' He explained that steel scalpels at a microscopic level have a rough cutting edge that tears into tissue , a function of the crystals that make up the metal . Obsidian , meanwhile , cleaves into a fine and continuous edge when properly cut . Dr. Green said he once helped documentary makers produce a program on surgical technology in ancient Egyptian , setting up a blind test on the cutting power of obsidian . Using cultured-skin burn dressing , a substance composed of skin cells , he made an incision with a modern scalpel and a parallel incision with an obsidian scalpel . The host of the program was then invited to look at the cuts under a video microscope and tell the difference . `` It was n't hard to tell the difference at all -- as soon as he turned around everyone in the studio was like 'Ohhh ' , '' Dr. Green said . `` Under the microscope you could see the obsidian scalpel had divided individual cells in half , and next to it the steel scalpel incision looked like it had been made by a chainsaw . '' Modern obsidian scalpels look nothing like the decorative flint-knapped knives of Neolithic man , often resembling their modern counterparts in everything except for the blade edge , but Dr. Green said they are a very different animal . `` The feel is very different because obsidian has no 'bite , ' '' he said . `` If you look under the microscope at a steel scalpel edge it looks almost like a saw , it has teeth , whereas obsidian is smooth even microscopically . `` It 's a very different feel to work with and you have to practice before you start using it in surgery . `` You also have to be careful not to nick yourself with it because you do n't even feel it ! '' And Dr. Green believes incisions made with these blades heal faster . He said a colleague who needed a mole removed agreed to undergo an experiment where half the procedure was carried out with an obsidian scalpel and the other half was removed with steel . `` What 's really fun is seeing it heal , '' he said . `` Four weeks later the difference was quite remarkable -- there was very much a difference in scarring . '' In Germany , the manufacturer Fine Science Tools produces obsidian scalpels which can be used in situations where the patient may have an allergy to steel or metal . `` For studies where trace metals from ordinary scalpel blades can not be tolerated , these very special obsidian scalpels may provide the answer , '' the company says . At €99 per scalpel ( $ 107.40 ) , they represent a considerable saving on their diamond cousins which the company prices at €712.50 ( $ 772.60 ) . But there has been little academic research into the efficacy of obsidian blades compared to steel scalpels , and they do have disadvantages : Obsidian scalpels are not Food and Drug Administration ( FDA ) approved , and they are extremely brittle and prone to breaking if lateral forces are applied -- meaning they are unlikely to ever be in widespread use . Dr. Green , whose scalpels were manufactured for him by an expert flint-knapper and archaeologist Errett Callahan , concedes the Stone Age scalpels are not for everyone . `` If it was let loose on the market there 'd be far too many injuries from it , '' he said . `` It 's very fragile and it 's very easy to break pieces off . ''
Obsidian can produce cutting edges many times finer than even the best steel scalpels . Some surgeons still use the blades in procedures today .