Something that seems easy or obvious to me may not be something my students have ever learned. As a teacher I have to be careful not to underestimate the potential of 'easy' projects. As it turns out, I found this information a) very helpful and b) very interesting. I did not expect to learn that much from a seemingly unnecessary project. This seals the joint between the blade and the handle, and enables the knife to be autoclaved.' Patterned after 'stone-age' knives which first made their appearance about 18,000 years ago, these modern versions utilize hard maple wood dowelling for handles and a special epoxy coating. Green receives his obsidian scalpels from an expert flint knapper, Errett Callahan. While it may seem odd to be using tools from the stone age in modern medicine, the blades being used today are different than those of ancient humans. In some cases this makes the relatively inexpensive obsidian scalpel a suitable substitute for an expensive diamond knife. These scalpels can be used for precise cutting in surgery. The blade is made from obsidian a type of volcanic glass which allows a much finer blade than is possible with the conventional steel blade. They are so fine that they are used in human surgical procedures where objectionable scar tissue might result from the use of a coarser scalpel. 'For applications where an extremely fine cutting action is required or for studies where trace metals from ordinary scalpel blades cannot be tolerated, these very special obsidian scalpels may provide the answer.

According to the fine science website, this accurately describes the tool and its uses: In a class of rocks, obsidian really is the sharpest tool in the drawer. I learned about technology by learning about technology.

Medieval obsidian scalpel make