Well, Radius, apparently Michbowguy has never heard of......The Amazing Ginzu knife! You can cut the Christmas tree to size, and cut through the super hard, and tough thin aluminum soft drink can, AND, yes, AND still slice a tomato! Lets see you do that with a rock! No, no, smashing the tomato doesn't count.
Heh, heh, heh, stir, stir, stir, the pot, merily, merily, stir, stir, the pot......or is that roll, been awhile since the sixties......
As for penetration of stone, versus steel, remember that stone is made of silica. You know like silicone lubricant. Steel, tends to grip, rather slip through. Also the serrated edges, or the stone point, has more surface area, and the thickness, and shape of the stone point has more shock value. The only draw back is how the stone point is hafted, and how the end of the shaft that the point is hafted to, is shaped. Whether it is bare, covered with, and smoothed with hide glue, or left un tapered, or smoothed.
Anyway, no matter how you look at it stone is sharper than steel. You can burnish metal to a smooth edge, but it will never be thin enough or smooth enough to come close enough to obsidian, or glass, or good flint, or chert. Like I said the only advantage with steel, is it's durability, and design features, and ability to take more damaging forces. A piece of stone, especially the obsidian, can cut you so bad you will bleed yesterday! AND you probably won't know it till you see the blood, or feel the sting when something like water gets to it. Back in the mid to late sixties, the Japanese used glass blades to slice the spindle fibers, of a deviding cell.
Stick Bender
