Crystalline rocks with obsidian’s composition include granite and rhyolite. Obsidian consists mainly of SiO2 (silicon dioxide), usually 70% or more. Though obsidian is usually dark in color similar to mafic rocks such as basalt, obsidian’s composition is extremely felsic. It is sometimes classified as a mineraloid. Obsidian is mineral-like, but not a true mineral because as a glass it is not crystalline in addition, its composition is too complex to comprise a single mineral. Tektites were once thought by many to be obsidian produced by lunar volcanic eruptions, though few scientists now adhere to this hypothesis. Having a low water content when newly formed typically less than 1% water by weight, becomes progressively hydrated when exposed to groundwater, forming perlite. Obsidian is the rock formed as a result of cooled lava, which is the parent material. Flint knapping was a hobby of mine when I was younger.A baroque cabochon of iridescent “rainbow obsidian”. In the Sierra de las Navajas (Razor or Knife mountains translated into English). Obsidian a type of volcanic glass can produce cutting edges many times finer than even the best steel scalpels. In fact as seen under a microscope, an obsidian scalpel will cut cells neatly in half where the finest steel scalpels will look as if they had cut through cells with a chainsaw. The chipped edges on blades and arrowheads, like the one pictured, can be very sharp, but what's really unreal is just the plain edge of a big flake knocked off a larger block.

Under the microscope, you could see the obsidian scalpel had divided. 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. Are obsidian blades durable Obsidian Blades It is very hard and of course, like most hard things are, it is brittle too. These edges can sometimes get much much sharper than your normal steel blades. TIL Obsidian blades are so sharp (3 nm thickness) that, on a cellular level, obsidian knives will cut between cells rather than tear the cells as steel. I used to cut my hands all the time and they would heal very quickly and with no scars. What I've read is that it is so sharp, that it is basically cutting between molecules and so leaves very little mark, or scarring.

Good quality obsidian fractures down to single molecules which can produce a cutting edge 500 times sharper than the sharpest steel scalpel blade ('American Medical News', Nov. I never hunted with any of my handmade points, as it's not legal here.Interesting! I found some flint while visiting my grandparents in AZ, a big enough piece for an arrowhead. On the cellular level an obsidian knife can cut between cells rather than tear the cells as a steel knife will do. I decided that I wanted to try knapping, so I went looking for more, and found some chert. 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. I tried knapping that, but it didn't go too well (I didn't try that hard though, just used a nail to chip off pieces. I couldn't get any chips to flake off the 'edge', the edge just kept moving closer to the center. But yes, those shards are sharp! I still have that 'perfect' piece, I'll have to work on it soon.

Obsidian scalpel cut