Science, Tech, Math › Science A History of Stone Tools, Then and Now Share Flipboard Email Print MmeEmil / Getty Images Science Geology Types Of Rocks Landforms and Geologic Features Geologic Processes Plate Tectonics Chemistry Biology Physics Astronomy Weather & Climate By Andrew Alden Geology Expert B.A., Earth Sciences, University of New Hampshire Andrew Alden is a geologist based in Oakland, California. He works as a research guide for the U.S. Geological Survey. our editorial process Andrew Alden Updated February 05, 2020 We all know the cartoon of the caveman bearing his stone ax. How crude life must have been, we may think, when there was no metal. But stone is a worthy servant. In fact, stone tools have been found that are more than 2 million years old. This means that stone technology is not something Homo sapiens invented — we inherited it from earlier hominid species. These stone tools are still around today. Stone Grinding Tools Start with grinding. One stone tool that's still in common kitchen use is the mortar and pestle, better than anything for turning things to a powder or paste. (Those are made of marble or agate.) And maybe you seek out stoneground flour for your baking needs. (Grindstones are made of quartzite and similar rocks.) Perhaps the highest use of stone today along these lines is in the tough, heavy granite rollers used for grinding and conching chocolate. And let's not forget chalk, the soft stone used for writing on blackboards or sidewalks. Edged Stone Tools If you're lucky enough to one day pick up an ancient arrowhead, the utter coolness of the technology really comes home when you look at one of these stone tools close up. The technique of making them is called knapping (with a silent K), and it involves striking stones with harder stones, or highly controlled pressure flaking with pieces of antler and similar materials. It takes years of practice (and cutting your hands a lot until you become an expert). The type of stone used is typically chert. Chert is a form of quartz with an exceedingly fine grain. Different types are called flint, agate, and chalcedony. A similar rock, obsidian, forms from high-silica lava and is the best knapping stone of all. These stone tools — points, blades, scrapers, axes and more — are often the only evidence we have from archaeological sites. They are cultural fossils, and like true fossils, they have been collected and classified for many years around the world. Modern geochemical techniques like neutron activation analysis, coupled with growing databases of the sources of toolmaking stone, are allowing us to trace the movements of prehistoric peoples and the patterns of trade among them. Stone Tools and How They're Used Today The knapper/artist Errett Callahan has devoted his career to reproducing all the ancient tools, then moving beyond them. He and other practitioners have brought this technology into what he calls the Post-Neolithic period. His fantasy knives will make your jaws drop. Obsidian scalpels are the sharpest in the world, and plastic surgeons rely on them more and more for operations where scarring must be minimized. Truly, the stone edge is here to stay.