heat treating in reverse?

[Prarie Bowyer]

So I see a ton of stuff on here about heat treating stone.  It looks like the stone is nearly unworkable then it gets cooked in some manner and it suddenly makes lovely points.  Can it be rehardened?  I'd think heating and quenching would shatter them but maybe not?

[ionicmuffin]

interesting theory! try it? maybe you will get some excellent results?

[Tower]

I wouldn't try it with any of my stone.

[stickbender]

     If you want cooked gravel, that is the way to get it!   I can make enough gravel, just TRYING to knapp, let alone, by going to the trouble of heat treating it, and then reheating it and tossing it in water, to watch it make all those bubbles, and hissing noises, as it crumbles into a million pieces.  Nope, more satisfying, making my own rubble pile, without heating, and getting to do the sacred %$##@!@ dance, and then either smash, or fling the almost really nice piece I was working on, till that hump showed up in the middle.....

                                                   Wayne


                                               Wayne

[Stringman]

I wouldn't call heat treated stone "soft." On the contrary, it is super hard. It also happens to be fairly brittle. There is no process for reversing that molecular change (that I'm aware of.)

The thing to keep in mind with any rock is: if it's workable dont heat it; if its not workable heat it. Also, don't make a brittle tool when you need a durable tool.

Scott

[Tower]

I have picked up debitage flakes from sites that date back thousands of years. Made some Beautiful points from them.  Once treated always treated. I don't think it can reverse, even with time.

[Bill Skinner]

You don't drop the hot points or bifaces in water, they'll shatter.  They'll shatter if you heat them too quick or cool them too fast.  If they are not heated enough, they can be reheated to make them more knappable.

[iowabow]

My heat treated Burlington will go through bone and not break, that is strong enough for me.

Two thoughts, heat treating will fuse/glue the quartz crystals to the ofter componets in the stone. Second your design can make the object stronger.

I am making my points now lens shaped with a distinctive median ridge. I moved to this so the point would be stronger. With all the misses this year, including one into frozen ground, not one point broke in half. I did resharpen one. Maybe this is a better way or maybe I got lucky!