Ryholite?

[bownarra]

Hi folks, my knapping bug has been reawakened!
Instead of having to buy rock I would much prefer to collect it myself. Now being a rock climber of around 15 years I know the local rocks and nothing jumps out at me. However we do have the Lake District within drivable range and most of the rock there is ryholite. I think I heard once that it is ok once heat treated?
Can anyone confirm if ryholite is an ok knapping rock type?
Also wondering about greenstone? I know it was made into axe heads (Langdale, Axe factory is a good search topic) but I think they were ground into shape?
Flint is the obvious answer but the decent flint is found around 350 - 400 miles from where I live. That's a bit of a drive on the hope of finding good stone!

[bjrogg]

I believe it is knappable. I have never tried it. I have seen points on here a couple years ago. I think it is pretty tough stuff.

Bjrogg

[Outbackbob48]

Bownarra, Rhyolite is like most knappable rock in can come in some great knappable to just plain junk and everything inbetween, I have seen some green rhyolite that James Parker had that was great knapping stone, rhyolite is extremely strong and durable and can be extremely sharp. Most that I have seen is just plain tuff hard rock, I don't believe it takes heat very well but I don't really know much about heat treating it, I do know that a pc of ryolite works excellent with flint and steel type fire kits. Hope this helps ya some. Bob

[bownarra]

Thanks for the information. I will pick some up and give it a try. Heat treating sounds like a fun project to try as well.
I've managed to get some big cobbles of flint. I will be picking up some bigger hammerstones for them. It looks like good stuff...but how to attack it??? 

[Parnell]

Be interesting to see what you can find.  I’ve had some success with it...like Bob said, JP’s green stuff and also some with black.  Had to definitely HIT it! Ha!

There is a place in Maine called Mt. Kineo.  I saw it on a fishing trip about 20 years ago.  Apparently it’s a giant rhyolite dome that at some point slid apart. Natives quarried it from all around.  It would be interesting to see about that in person, someday.

[JackCrafty]

Rhyolite does not respond to heat. It doesn't matter how much heat or how long you heat it, it will stay the same.

I have some videos of me working rhyolite from NC.  I use aluminum flakers and a hammer stone in this series. Here's the first video out of 6:

https://www.youtube.com/watch?v=kkZoLrO_O7c

[Allyn T]

Does soaking it in water help?

[JackCrafty]

No. Soaking in water doesn't appear to help.