Umm, thanks but no thanks. If you want some internet points here you go: The crystal/grain size of the stone seems a little coarse to be a tool. Sharp egdes can only come from fine crystal/acrystal rocks like obsidian or flint (which is an ambiguous term for many forms of chemically produced fine crystal silica-based, sedimentary originated rocks). Chalcedony is an example of something that would fall into this.
And that said, archaeologist are the worst geologists. So much so that they cannot really talk to each other without samples in hand. Basically, Archaeological geology diverted from Geology about 60 years ago and the mutations have been severe.Try to pin anyone down on the definition of dacite (with an example)and you might as well be talking about the war again.