Author Topic: Rocks?  (Read 1649 times)

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Offline bushman

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Rocks?
« on: December 22, 2011, 12:46:07 am »
I while back I asked on here if you could melt down or really heat up any rock and turn it into something knappable. Well, I got my answer this fall while I was out hunting. On a mountain I came across a few different landings that had a bunch of slag where there was slash piles. Most of it was all full of holes and worthless for knapping.
On one of the really old landings, there was so much of it that it covered a 30 foot circle at least, and there was moss growing over it in places.
Most of it was really light and all follow of holes but I found one piece that was melted on the outside and still solid on the inside. I gave it a whack and a flake came off, sounded like glass when the flake hit the ground. The nicest rock I have found yet around here for knapping, but it was mostly ½ inch thick but had a ¼ inch thick dip in one place and only 1.5 inch wide so didn’t think I would get much from it. Put it in my pocket and looked for more. Didn’t find any more like that but came across a big rock on the edge of the circle that just had a little bit melted on the outside edge, and it was all heat fractured, I busted off a smaller piece to take home, the rock looked like a type of rock that is very common all around here (I tried knapping it a few years ago, didn’t work.) It is a type of lava rock I think.
The un-heated rock isn’t rusty but a magnet (I used a rare earth magnet) will stick to it but it doesn’t really deflect a compass needle. The magnet will stick but not that great to the rock that was heated and just melted on the outside edge. The magnet barely stuck to the solid piece of slag. And the magnet wouldn’t stick to the piece of slag.
I tried to make a point out of that solid piece of slag but I was right, where it was thick I hit a little too high up with my billet and I snapped it.
First picture is of the rocks lined up left to right from the un-heated to the slag. Next are some close ups. And then the snapped biface. I need to get back up there and look for some more of that solid slag next year. I wonder what temperature and for how long it was needed to melt that rock, probably a couple of 1000 degrees C, slash piles get really hot and burn for up to a few weeks or more.
Do you guys got any idea as to what it is? Is it all the same rock like I thought?
Thanks for reading.
Bushman











Offline bushman

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Re: Rocks?
« Reply #1 on: December 22, 2011, 12:48:33 am »
The next 6 pictures are of another rock I found, I thought it was a piece of agate when I first saw it, but after I knocked off some flakes it looked like granite. It did flake but not all that great, I treid to get the flakes to travel across the tap but they wouldn’t so I gave up. The cortex on it is a 1/16 inch thick and looks like the black stuff in granite, it was all around it on the outside, minus one edge, that looked like it was ground by a glacier. Any ideas as to what it is? Thanks for looking.
Bushman