Flint, chert, and obsidian arrowheads were and are made by flaking and chipping at the stone with other rock, bone, and wood until the desired edge and shape is achieved, in a process called knapping.
There are two different flints. One is natural rock (used in flintlock firearms) The other is the "flint" in a cigarette lighter. That is not truly flint, but Misch metal, composed of iron oxide and...