how sharp can a rock be, anyway?

[radius]

Just how sharp can a rock really be?  I mean, come on:  sharper than steel?  AS sharp as steel? 

[stickbender]

     Osidian, or volcanic glass is far superior to steel in sharpness.  They have done surgery with obsidian blades, and they were far sharper, and the edge lasted longer than the modern scalpals.  Look at a metal edge under a micro scope, and it will look like an old abused saw blade.  The stone point has a molecular edge, and is very smoothe.  Flint, chert, and other similar stones will likewise produce a sharper edge than steel.  The advantage to steel, is it's ability to absorb more schock without breaking, and to flex.

[ricktrojanowski]

If you get a chance work with some obsidian.  You''ll find out the hard way how sharp it is.

[Justin Snyder]

What Stickbender said.   A sharp obsidian edge is the sharpest edge known to mankind.  It is often one molecue wide at the edge.  Justin

[D. Tiller]

Yep! I have the spilt blood to prove it too!

[radius]

ok, ok, now that we've got obsidian out of the way (which i knew about, of course) let's talk about some of the other stones people use to knap, like chert or something.

[Pat B]

Still sharper than steel!     Pat

[Justin Snyder]

It probably depends a little on the stone.  If you get good stone it will be sharper than steel. (especially if I sharpened the steel)    I'm sure that poor quality stone will give you a poor quality edge just like poor steel don't hold an edge as well.  Justin

[DanaM]

Stone can be sharper than steel but steel will be more consistent, from what I've seen most stone knifes are more like a saw edge
which won't give a smooth cut. If ya just knock a flake off and make a hoko knife then yer talkin sharp. Not sure I explained taht real well

[Coo-wah-chobee]

Well Radius...........let me put it this way....Hope ya never get cut by it !  Stone that is.  I disagree with Dana, stone can be as consistent as steel. When stone breaks it produces another sharp edge steel does not.................bob

[david w.]

Stone gets really sharp!  I was knapping yesterday and had some flakes that were way sharper than steel.

 Glass also gets wayy sharp

[michbowguy]

OBSIDIAN IS THE ONE OF THE ONLY KNOWN MATERIALS THAT CAN SPLIT ITS OWN MOLECULE!!

obsidian is wayyy over 100 times sharper than any surgical honed edge.

rock has been putting red meat on the dinner table for THOUSANDS OF YEARS, who are we to question its ability?

mbg

[radius]

what do you mean, "Who are we to question it?"  You sound like rock is a god, and we are some ignorant prehistoric savages!  Jesus!

We have minds so that we can question.  (well, that's one thing to do with our minds, anyway!)

I have never knapped, so I don't know...hope you don't mind me asking...

[Hillbilly]

Stone can get really, really, really sharp. All the scars on my hands illustrate it well. A stone edge feels different from a steel edge, though-so many people not used to it would think that a sharp knapped stone edge was duller than a steel one, but it'll sure slice the bejeezus out of meat. I've surprised a few people by picking up a "dull" piece of flint and slicing through heavy pigskin leather like it was butter.

[cowboy]

I would say, it all depends on how ya knap or finish the edge. The edge of a spall that tapers out unworked is like a razor, but on the points that have the edge chipped and shaped it's more like a serrated steak knife - not razor sharp but does go through hide, bone, and meat nicely .