Primitive Archer

Main Discussion Area => Flintknapping => Topic started by: Mafort on December 10, 2020, 03:06:07 pm

Title: Can you knap agate?
Post by: Mafort on December 10, 2020, 03:06:07 pm
Saw some agate slabs on Etsy and I was wondering if you can knap it into an actual usable point...
Title: Re: Can you knap agate?
Post by: JEB on December 10, 2020, 05:49:19 pm
I have knapped agate slabs into points and blades. I cook it up 1st. Photo of it would help get you the right answer tho.
Title: Re: Can you knap agate?
Post by: Mafort on December 10, 2020, 07:54:57 pm
They’re labeled as coasters. Just flat pieces of agate that have been cut into flat slabs
Title: Re: Can you knap agate?
Post by: Tower on December 10, 2020, 08:21:57 pm
Probably dyed Brazilian agate.   It will heat & knap.   I have made several points out of coasters, but the artificial color can fade w/ the heat. .
Title: Re: Can you knap agate?
Post by: Mafort on December 10, 2020, 09:43:40 pm
Can I heat treat this stuff in the fire pit during the next fire we have and let it cool naturally?
Title: Re: Can you knap agate?
Post by: JEB on December 12, 2020, 09:43:56 am
Patrick (Jackcrafty) may be able to answer your fire pit question. I use a turkey roaster and Lake Michigan beach sand.  Youtube has vidoe's on how to do it also.
Title: Re: Can you knap agate?
Post by: JackCrafty on December 12, 2020, 08:39:30 pm
Yes, you can heat treat agate slabs next to the fire if you keep the wind off the stone and make sure the heat doesn't go too much above 350F. If it doesn't heat well at 350F you can go higher next time. It doesn't take long and I usually try to maintain a good temperature, by steadily adding more coals, for about an hour and then let it cool down naturally.

I heat the stones by feeling the heat coming off the fire. I've got experience cooking at 350F - 400F on the grill so I can kind of judge the temperature. Otherwise, you'll need a thermometer or some other device to check the heat.

Don't let the coals touch the stones but it's ok if you can't help it. Just don't let big coals touch the stone. The stone should be just barely touching the ashes at the perimeter of the fire. Also, make sure you are only using coals for the heat. Flames are going to cook it too fast and when they go out the stone will cool too fast.

Try the technique on stone that's too small to work or contains defects before you put the good stuff next to the fire.
Title: Re: Can you knap agate?
Post by: kbear on December 27, 2020, 03:21:48 pm
That picture right there, worth a thousand words...... Thanks Patrick!