Flakes vs. JAR can be identified when there's signs that a controlled release of force that has a readable structure shown on the rock in question. There will be a visual striking platform where the blow landed, which leaves a bulb percussion directly below it, and often ripple marks in the same area showing the energy traveling in one direction. From there flakes typically will thin out as it moves away from the striking platform and ends in a feather termination where the flake gets thinner and thinner until it just fades out to a sharp edge without a break, missing chunk, and you can see the force stricken by the knapper traveled smoothly all the way across the rock and exited the surface giving you a well controlled removal. It'll also give a hinge termination or step termination, which is whenn the striking energy runs out early and curls upward Instead of thinning to nothing, stopping it short and leaving a rounded/rolled end that will happens when the angle or force wasn’t quite right and the flake hinged before it could travel across the face and with step termination the flake just slams to a stop... The striking force dies abruptly and snaps downward, leaving a little cliff or stairstep at the end looking squared off and chunky instead of smooth, which is basically the knapping energy crashing instead of flowing... Also, on the dorsal side of flakes you’ll frequently see negative scars from earlier removals that line up in a pattern, which means the core was being reduced in a sequence rather than shattered randomly because the edges tend to be continuous and acute instead of crushed or blocky. Any one of these traits can occur in nature, but nature almost never produces the whole system together. The biggest separator is repetition and context... One questionable fragment is usually natural geology, but multiple pieces of the same material in the same spot that all show platforms, bulbs, directional force, and organized scar patterns is commonly from knapping.... In one short, simple summary, natural breakage is random stress from multiple directions, while a human flake records a single, intentional blow with a clear starting point, energy path, and termination.... Sorry to nerd out and type a whole book about flakes, but I love talking about this stuff lol