Home Forums Hunting & Shooting Hunter's Campfire Knap obsidian

How big do the pieces need to be to be worked. I just went through me 6 year old daughters bag and she has a lot of small pieces that might be too small to work with. She does have several that are roughly tennis ball size and a few that are baseball size or a bit bigger.

I'll go through my 4 year olds bag later. It was pretty funny seeing my 6 year old try to carry her pink paw patrol back pack full of it. The back pack weighed more than she does.

Bb

Burleyboy:

I can work with cobbles down to about tennis ball size, but most of it will be waste. The larger the better. When I go rocking, I carry a soft hammer, find likely stones, and knock off pieces that might be from 1/2 to 1 inch thick. Those go in the bucket and the rest stays in the field. Again, one has to learn to work the proper angles to get usable slabs.

There is no need what so ever to heat obsidian, as it's the most easily worked material generated by Mother Nature. There have been rumors the natives heated stones and then dripped water on them to pop off the undesired portions. That is total BS, as one has absolutely no control over where and how his rock might crack. If one gets to middle America with flint and cherts, then heating makes spalls much more glassy and workable. I don't have the numbers in memory, but one can find data on the temps and durations needed to heat those materials. Still, they are a bit harder to work than obsidian.

As to selling raw obsidian: One can improve his marketability if he can chip off thin and relatively flat spalls. With luck, one sometimes finds a area where the obsidian was formed in sheets, and one can simply pick up nice thin pieces. Not the case in most instances though. Simply sending folks a pile of rocks will result in a lot of expensive waste, unless they own a rock saw. I start with a large rock maybe 5 to 10 inches across the long axis, and can sometimes hammer off 3 to 4 usable slabs. With a rock saw, I could get maybe 10 usable slices, cut those to the desired shapes, and end up with a lot less waste and absolutely straight points. We have numerous pros around the country that go that route, and they can generate gorgeous work with perfect herring bone flaking patterns. Far from an authentic method though.

Link to site selling sawed preforms
No connections to that link.

Given my location, however, I can pick up a 1000lbs of obsidian in 20 minutes and know of some spots where a single stone might weigh that much. Even have the black stuff in Cookie's flower beds and scattered over my back 40. Most of my yard stuff is not much larger than a baseball. Still, materials and waste are not a consideration for me. I'll never ever use it all.

Busy traveling tomorrow, but I will take some pics of my raw materials and tools on Friday and post them up.

I picked a bunch up last time I was in that area. Still haven’t tried to do anything with it.

I didn’t have much interest in it but I found a piece about the size of a basketball and figured it’d make a big spear point..it’s been sitting in the flower bed here since lol

I took some pics of some of the bigger pieces but I don't have a picture hosting site and don't post pics. I can text them to someone if they want to see them or post them here for me. Just PM me a mobile number I can text to.

Thanks,
Bb

About a day late, as I said I'd post a few pics. Will do this in two posts of 4 each, as I'm not sure I can exceed 7 images in a single post.

First tools of the trade. If one goes toward the historic methods (left side), he'll have several antler boppers made from the ground down bases of deer/elk/moose antlers. One just uses these as hammers.
Next a pressure flaker from an antler tine, and then some abrading stones to rasp down sharp edges.

Pics are backed by a 1-inch grid.

If he goes modern, one uses copper boppers. These are copper tubing end caps hammered to a bowl shape, lead added to fill the bowl portion, and a handle of choice epoxied on.
A pressure flaker of copper wire inserted into a handle of choice, and an abrading stone (carbide) that makes quick work of rasping down sharp edges.


Here are some smaller obsidian cobbles as one would find them out in the desert. These are about as small as I care to work with, as it's difficult to break these down such that one has a flat surface to start with.


More rock hammered from larger stones down to the form I like to bring home. This leaves most of the waste in the field. The thickest chunk here is about 1 1/2 inches on the right, and that's the stone I'll work down here.


If one gets lucky, he can sometimes hammer off very thin slices demanding little in the way of thinning. Both of these are about 1/4 inch thick.


More to come.

Here is the outer weathered surface of my rock of choice. The first chore is to hammer off this scabby surface. My plan is to have the lower left as the base, the upper right at the point, and its present greatest dimension is about 5 1/8 inches.


Working in from the sides, we have all of the weathered surface knocked off and a little shaping started. No length loss and about 3/4 inch thick.


Now it's down to the approximate shape and is just under 1/4 inch thick. A bit transparent as one can see through the outer edges. Next task it work on the point to get it aligned with the overall centerline of the piece. That will simply involve knocking off a bit from the upper edge of the tip. To this point all work has been done with the largest (1 inch) copper bopper and we have not lost any length.


Damn! I knew I should have gone to the smallest bopper, but thought I could pull it off. Most breakage occurs when one is working one end or another.
Thus are the vicissitudes of life. Sadly, looks like I ended up with nothing but detritus. Could work the two pieces, but the break took the wind out of my sails.


It happens. Presently I have about a 90% success rate with the big ones. According to the image time stamps I had 40 minutes into working this piece with some of that devoted to snapping the pics. Much less of an issue with smaller points.

Have a good one, damn it.

Great pictures 1Minute! I really like the selection of tools you show. You don't need any more than that. I use a mixture of tools, both traditional and modern. When choosing a tool, a lot depends on the type of stone I'm working, but I've never had much luck using a antler tine for pressure flaking. I love a piece of antler that I use for a big bopper though. On some of the tougher flint and if I really need to do some serious thinning, without screwing it, up I'll use indirect percussion. It gives me much more control.

I had an old Cherokee Indian friend (well, he was retired, about a year older than me and he is a Cherokee) showing me a few things about knapping. He put a mark on the edge of a piece of cardboard, handed me a pencil and told me to hit the mark with the pencil point. It was eye opening...Every time I tried it, I was a 1/4 inch to the right. That explained a lot of the problems I had when I was starting out knapping. I really had to work on my aim to get to the point I could hit a piece of flint where I wanted to hit it.

Mathsr:

Good to hear from you. I do need to get into some indirect percussion to maybe reach the midline with finishing flakes. Tried a little last spring and it did launch some long flakes, but I've not put together some proper tools.

Thought about starting over after my break this afternoon, but decided I could own up to my one failure in life.

Might try another photo run in a day or two.

Have a good one, and put some stuff up once in a while,

Later,

I like to watch this guy:
https://www.youtube.com/user/AllergicHobbit

Snyper:

Yes, there are a lot ways to skin a cat and some great videos out there. Regardless of technique though, one simply has to break a lot of rock to master things.

Cool

I been wanting see your bop tools and flakers.


I have found several hammer stones in with the debitage and blades. A couple I have look as if they’ve been battered thousands of times. And theyre more of the quartzite composition, mostly limestone around here.

I’ll dig out a couple if i can remember with bucket theyre in

Now that is a hobby...thank you for the presentation.

Thanks 1minute its interesting seeing a bit of your tools and work. I tried to shape a small piece for them the other night and got pretty close to the rough shape of a smaller arrowhead but I could not thin down a thicker side. The kids were impressed anyways.

I don't think I have what it takes to really pic this up as a hobby but its been a fun lesson for the kids that started from a little home school history lesson that grew into a road trip, overnight camping activity, search and collection, and then a business lesson as my 4 year old sold a box of obsidian for $10 and then boxed it up and will be mailing it out.

Next time we are out where obsidian is thick i'll have the kids focus on big pieces. We've got about 74 pounds of smaller pieces that will probably get hoarded until I get an opportunity to accidentally lose them.

Bb

Burleyboy:

A little reading on the proper angles and some experimental rock breaking and one can actually progress quite quickly. One can actually begin with a rock shaped like a box turtle, hammer off all the curvature bringing his working surface toward the flat side, and end up with piece about 80 or 90% of the original length. Of course if one can begin with flattish pieces, it's considerably easier.

The kids are a bit young yet, but it might be an endeavor one can keep on the back burner for couple years. I think I enjoy it simply because each piece of stone is a new challenge.

Stay cool. Getting a bit toasty over here.

Slumlord:
Yes. I should have included a couple hammer stones. About any good round river rock will work for knocking off large chunks, but they do tend to shatter more material. Big copper hammers or moose antler butts are the best. Seems the softer materials make contact, actually compress a bit biting into a rough surface, and finally enough force arrives to break the desired piece off. Actually a micro-second event, but quite different than being hit with a hard piece of steel that has no cushioning action.

Been fun, and I'll take another stab at a successful run in a day or two.

Have a good one,

in situations like that I consider it to be "keeping the piece" - interpret that either way. BTDT. :}

Good one!

Some pretty amazing skill on display 1minute. Thanks for the explanation.

Here are a couple of pictures of my tools and a point made of Georgia flint and a few points and blades that I have completed.

The point of Georgia flint took about 15 minutes from a flake that was three inches long with a 1/2 inch thick impact bulge at one end tapering down to nothing at the other end. I hate this kind of flake and usually just use them for practice. With this kind of flint I run about 50% on getting a presentable point out of them. It is hard, tough, and has a lot of faults in it. I really have to watch myself when I go back to obsidian because it won't take the kind of strike you have to use on this flint. The little pile of chips and to the left is what is left of the original flake that didn't look like it belonged on a point.

The tools are resting on a leather pad I use to cover my leg. I use a piece of horse stall mat (black rubber piece just below the abrading stone) with a grove in it to support the flint while pressure flaking. It does a great job of keeping the flakes out of my hand and absorbs a lot of the shock from the tool.



The blade on the left is made of obsidian and is 5 1/2 inches long, 2 1/2 inches wide and a little over 1/4 inch thick. The next two are made of noveculite from Arkansas. The green point is made of glass from the bottom of a wine bottle. The last point is a copy of a point I found on the Ogeechee River when I was a boy. It is 1 1/2 inches long, maybe 1/8 inch thick and made of chert.

Nice work there Mathsr, and you do have some tough materials to work with. Need to hustle up some flint if I ever again traverse the US in a rig.

Forced myself to go out with Cookie's camera and give it another try today. This will be two series of 5 pics each again with a 1 inch grid.
This first image is the rock as I picked it up on the range. This side is relatively flat, and I did knock out a chip to see what the color/pattern might be. The upper and lower stones are there solely to hold down the gridded paper. The objective here will be to generate a long slim lance shaped point. There is a lot of thinning to do, and not a lot of room on the sides to work with. The left end will form the base, and I'll try for the point on the right end.


Side two, and it has a bit of hill in the middle giving it a thickness again of about 1 1/2 inches. First efforts are with my larger copper bopper and focus on getting the weathered surface off and chiseling/smoothing down the hill on side 2


Side 2 with the surface cleaned and about 1/2 of the hill's elevation removed.


Now back over to the side 1 flatter surface to clean off the weathering there.


Side 1 is cleaned off and some shaping has occurred. At this stage we have not lost any length to speak of. Next efforts will focus on straightening out the slightly curved bottom edge making it parallel with the upper.


Going to the second post.

The sides are nearly parallel here, but I need to get the tip chiseled off so it's more in line with the centerline. That involves chipping off a little from the bottom side of the tip, and will cost one a small bit of length.


Having learned from yesterday's mishap, I got it done this time using a pressure flaker.


About all that is left to do is to clean or true up edges a bit. This looks pretty good, and the final step is to chip in some notches.


Finished product and my pile of waste. One could recover some of the inch+ flakes from the pile and pressure flake a few smaller points. Most of this is garbage, however, and will end up in the local dump.

Looks like we fiinished with about a 5 1/2 inch piece. Centerline from base to tip is a little less than 1/4 inch thick and I lost about 1/4 inch in length from start to finish. Image time stamps say I consumed 1 hour 19 minutes.


This last image is the same point immersed in a shallow pan of water. Seems to eliminate the glare and lets one see the pattern/colors more clearly. I did not use Cookie's tripod, however, and it seems I had some camera motion. Not a shot to be proud of.


A bit less frustrated today and will now huddle inside to escape today's 100 degree heat.

Have a good one,