Use of Hammer Stone & Soft Hammer Percussion To Create Chips From Large Pieces Of Obsidian (or Flint or Chert)

Some folks have asked about percussion knapping and making small pieces (chips) for making arrowheads from large chunks of knappable stone, such as obsidian.

Once you have a local source of obsidian, then it is useful to have some kind of appropriate hammer device with which to break small pieces off of large pieces. You could use the old type tool, the hammer stone. Get a nice round river rock of granite or some other hard type stone. If it is heavy enough for its size, mass is important for this activity, then you can use it to break corners off of large pieces of obsidian.

Do not try to hit against a flat face on the target stone. Any fracture will initiate going into the mass of the stone, and only create cracks inside the chunk, not break off small pieces which are usable. Instead hit near a corner, and aim the fracture to follow along a ridge or edge on the surface.

Always wear leather gloves, and support the target stone on the ground, or on a thick leather pad. Also wear safety glasses, as small chips will fly.

A modern alternative to the hammer stone is to use a copper billet. I use a copper rod, 3/4" in diameter, by about 5 or 6 inches long. The end is rounded off by impacts. This is heavy enough, yet the metal is soft so it won't crush the target stone.

If you use a steel hammer it will just crush the natural glass.

The idea is to control the fracture. Obsidian naturally fractures in a cone shape, just like glass. If you have ever seen a hole in a thick glass window pane made by a BB, then you will know what I mean by a cone. The fracture radiates out from the point of impact at about 70 degrees away from the line of impact force.

The key is to align this fracture plane just under the face of the piece of stone which you are trying to break. That way the fracture plane travels just inside the stone and travels a good ways as it breaks. This can give you a nice long chip. Remember, you are in control of the stone, so you can tilt it to align the angles the way you want it to break. Practice hitting the stone in the same way or direction most of the time. Then you can modify the breaking angle by tilting the target stone, not changing your swing of the tool.

It takes practice to develop a feel for the angles and the direction of fracture.

I would suggest getting a couple of chunks and just breaking away at it to get the feel for the directions and force needed.

Good luck, and always utilize the safety gear.

F. Scott Crawford

Carrollton, Texas

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You are invited to visit my web site for more background information and photographs related to the making of arrowheads: http://www.arrowhead-makeyourown.com/

For fully photo-illustrated process information related to the making of an obsidian Gunther style arrowhead, plus photographs of a number of ancient and authentic Gunther type arrowheads, you are invited to visit my other web site: http://www.arrowhead-maker.com/

Now Available: an iGoogle Gadget showing Clovis Point percussion knapping

One of the fascinating projects to which flint knappers of all skills pay attention is to the making of Clovis Points.

I have heard from several new knappers who are eager to try their hand at this particular ancient style of making a spear head.

For those of you who have an interest along this specific line, a few summers back I made a series of photographs of a highly skilled percussion knapper as he worked on a large obsidian Clovis spear point. This took place at a Knapping Workshop at Glass Buttes in eastern Oregon.

These photos have been linked together for your viewing in an internet device called a "gadget" which can be placed on your home page.

This is a link to this new Google Gadget which you can load on your Google home page if you are interested in making Clovis Points or other flint knapping projects: Mikey Makes A Clovis Point

See Mike Make A Clovis Point

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Here is what iGoogle says about this gadget and how to use it:

Your friend has created something special for you to see every day on Google. The gadget will be available on your own iGoogle page. To go with this new gadget, you can also personalize your iGoogle page with the stuff you like. Your friend's gadget will change from one day to the next, so visit iGoogle daily to see what's new!

You can get back to your iGoogle page by visiting Google and clicking the iGoogle link in the upper right hand corner.

Want to share a message or photos with a friend every day? Then sign in to iGoogle and create a gadget of your own to send to friends.

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Thanks for participating in flint knapping and arrowhead making projects with us. Once in a while, I will be creating additional "gadgets" such as this one, with a new series of related photographs which will be of interest to flint knapping enthusiasts. For instance, I have already created the next gadget about Clovis Points to show the completion of the sequence started in this first gadget: Mikey Makes A Clovis Point. It will be available in a week or so.

Sincerely,
F. Scott Crawford
www.Arrowhead-Maker.com
www.ArrowheadCollectingOnTheWeb.com

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You are invited to visit my web site for more background information and photographs related to the making of arrowheads: www.Arrowhead-MakeYourOwn.com

For fully photo-illustrated process information related to the making of an obsidian Gunther style arrowhead, plus photographs of a number of ancient and authentic Gunther type arrowheads, you are invited to visit my other web site: www.Arrowhead-Maker.com