Fire Scars on points

[Cannonman17]

Just bored so I thought I would share what a fire scarred point looks like, here's a classic with a large popped out chip in the surface. Chert often has tiny air pockets that when put into a fire sometimes can, and do "pop", either fracturing the point or blowing out a small inverted conical divit like this one.

[Rockhunter in Ohio]

Nice example! My understanding is that fire pops happen because the flint has moisture in it. When the water becomes super heated it turns to a gas and then the pending pressure causes the flake to pop off.

Cheers!
John

[Cannonman17]

I've heard that it's water also- I don't know if it's air or water pockets that cause it really, I lean towards air pockets only because I have seen them when I have broken open nodules of chert for flintknapping, on the other hand I've never broken any open and noticed any moisture although I suspect that it would be such a tiny amount that I wouldn't have noticed it anyways... I don't know.

[Vicegrip]

Hey cannonman ,
Remember this one. I found it while we were sifting pottery.

[Cannonman17]

That's a good example to- and to tell you the truth I don't remember it- I see what site it came from though.... did you know that all that land got sold off to new private owners? How depressing is that! Our "sites" are becoming fewer and fewer each year.