Not always, It depends on how it was chipped and if the stone had any flaws. Not all cherts are knappable or make those nice flake fractures. Inclusions also can change how well the rock flakes. It's why certain sites are well regarded for knaping flint, and flintlock strikers, but the vast majority isn't any good at all.Quote:
They tend to flake smooth like flint
Those fractures are only every produced by mechanical action as well. Hitting it, dropping it ect. Fire or freezing damage will not produce them.
The rock I have has a small chip that isn't flaked at all, that runs with a natural crack.
Those larger ones could have also been where the natural skin of the rock was, Have a look at my Thornwick images again and look at the skin layer and how it moves about.
This thread on a knapping forum explains it pretty well.
http://www.arrowheadology.com/forums...cked-rock.html