How do archaeologists know when they are holding a stone tool and not a rock?

Question

I've looked closely as some displays of rocks gathered by archaeologist in my area, and I never would have known that some of them weren't just plain rocks.

Answer 1

The real stone would have one cracked face and even perhaps two but is human made when the seemingly stone has many facets that only a blow produced by purpose to create some thing that can be used , like a spear head , stones to scrape animal skin , a rudimentary stone knife or a sort of a mallet or sledge hammer or the likes ... nature does not produce symmetrical many facet stones , you could say that slate or shell rock has flat plains but they are at random sizes and in the wrong place , verses in an area that could have been habit-ed by ancestors .

Answer 2

I guess that's why they're archaeologists and you're not. I wouldn't know the difference.

Answer 3

I remember reading of an experiment where the anthropologist placed food in a container that required sharp objects to open, then showed the chimp methods of flint napping to create sharp tools.  The chimp, when presented with the problem, simply picked up some stones & threw them at a boulder until one broke with a sharp face.  He then used this to open the container.  The anthropoligist had just discovered how the 1st homonid made the 1st tools.

Many tools will show repeated precussion marks on the stone that are indicative of some attempt to break or shape them. This does not happen normally in nature, but could happen during a rock fall & later be washed to another area by a flood. However many broken rocks in one area is not natural.

Answer 4

One can usually tell if the rock has been shaped using another harder rock or something. It will be evident in markings on the rock and the shape of the rock. Like flint rock can be broken and chipped away with using another harder rock. It will actually become sharper than the tip of a pen. If one looks at a pin under a microscope one will see that it will come to a blunt point. Flint rock will actually just keep getting smaller and smaller so it was a wonderful tool to use as a knife. The bad thing is that it does chip and flake off easy. So one could not use it to say cut threw a bone of an animal or anything. Like I said it will be evident upon the rock itself. One can actually see how it was shaped by some process.

Answer 5

Sometimes it's difficult to tell, especially when it's very early technology. However, a stone tool will look "worked" not like it was created by natural processes. Also, it may be found among other more obvious stone tools and in association with a campsite or a known tool making locality. These scientists are very specifically trained to know what to look for.

Answer 6

Well, there are various things that we look for to determine whether we have an artifact or an arti-FAKE! Some broken stones look so much like they really coould be something- and they turn out to be wanna-bes. It took some time and experience for me to recognize the real deal- especially when you've just recovered it from the ground. Sometimes, we just collect things we're not sure about and take it back to the lab for a closer look, after cleaning, under the 'scope. There are distinctive markings when stone has been deliberately worked or used, as opposed to natural wear/erosion. Even then, there are usually a few that get tossed in someone's garden because they turn out to be an AFR. (Another F-ing rock.)

Hope this helps. Unfortunately lithics (stone tools) are not my personal specialty.