The term "Stone Age," a misnomer, describes any tools from human prehistory not made from metal. The greatest challenge with identifying Stone Age tools is that many items, such as bone and wood, have disintegrated over time or, in the case of stone, weathered and eroded. Although the task of tool identification may seem daunting, following these methods can make Stone Age tool identification easier and enjoyable.
Read about the area where you found your stone "tool" or "manufacturing site" or where you plan to explore and the type of stone local to that area. Also read the works of archaeologists and the history of the people who once lived there (or nearby). Finally, read about or watch video documentaries that explore stone tool manufacture and reproduction.
Look around the area near your "site" for additional signs of Stone Age human habitation. This may seem like common sense, but many amateur Stone Age tool hunters forget that the Stone Age toolkit not only consisted of arrow heads, axes and scrapers, but included stone implements such as grinding stones in various shapes and sizes (look for unnaturally shaped ground surfaces, smoothness, and scratches or rubbed in grooves). Grinding stones (especially heavy, long food and grain grinding slabs), along with other archaeological evidence, such as post holes and hearths, point directly to human habitation.
Identify the type of stone located at your "site." Prehistoric humans used fine-grained or non-crystalline stone (for example, flint, quartz, shale or obsidian) that easily flakes when percussed to make some tools. Flaking stone by hitting one stone (the percussor or hammerstone) against another (the core), produced flakes of stone and continued flaking created serrated edges for cutting.
Search for local stone or large local raw material sources (for example, rocky outcrops or river beds) within a several mile range of your "site" as prehistoric humans tended to use readily available stone to manufacture tools. Evidence of manufacturing may be at the source site and not your own. If the "tool" at your site is not made of local stone, then you likely have a true artifact. The archaeological record and modern anthropological studies suggest that hard-to-find stone materials or tools were traded between prehistoric peoples just as modern humans trade goods.
Review the tool making trends of each of the Stone Ages (i.e., Paleolithic, or "old Stone Age," Mesolithic, or "middle Stone Age", and Neolithic, or "new Stone Age") and compare to your site findings.
Think ergonomics and hold your stone "tool" in your hand. Stone scrapers, made to easily fit in the hand, often included a "thumb rest."
Building your knowledge base by combining research, traditional archaeology, modern stone tool reproduction techniques and ethnoarchaeology will improve your ability to look at a site and identify if the artifacts are from human origin or a work of nature.