Retsup99, I believe that is a replica of an obsidian knife similar to ones used by the Native Americans in the South West.
I can actually make some tools out of chert, flint or obsidian( a natual volcanic glass). The process is called flintknapping. It involves taking bone or antler tools and striking off pieces of the stone until the desired shape is reached, then further refining the tool with a sharpend antler with what is known as pressure flaking. Try looking up a man named D.C. Waldorph and watching his video. He is a master flintknapper.
Tools like this are very sharp and effective, despite being old or "obsolete".