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Roger Weller, geology instructor regional geology planetary gems
The Making of Arrowheads
Arrowheads can be found through-out most of the United States. Arrowheads can
be made from various materials: bone, antler, scales, flint, chert, jasper, and
quartz. The arrowheads found in some areas are unique because the type of rock
or material can not be found in the area for hundreds of miles, so this leads to
the belief that the rock used for arrowheads were traded for. The steps for
making arrowheads sounds easy but is a art and takes time and patients to
The rock used for the best arrowheads is flint; this is a sedimentary rock that when it is chipped it forms a very sharp edge. Flint when chipped leaves a conchoidal fracture, Webster’s defines conchoidal as a “Greek word meaning: like a mussel; or having elevations or depressions shaped like the inside surface of a bivalve shell”.
Flint is a chemical sedimentary rock made of cryptocrystalline
(very fine-grained) quartz. It is distinguished from chert by its more shiny surface and its better ability to be chipped into sharp implements such
Some of the areas flint can be found is in the Ohio valley, North Carolina, Arkansas, Oklahoma, and Utah.
Another material used was scales from the gar fish; this was used by the Seminole Indians of Florida. The gar has heavy ganoid scales.
The Seminoles used these naturally, very hard scales for the heads for their arrows and lances.
Obsidian or volcanic glass was also used.
Obsidian can be found in Yellowstone park region and other volcanic areas. Obsidian also flakes in a conchoidal fracture making it very sharp.
Obtain the tools you will need to shape your arrowhead. You will need a large
piece of antler for shaping large rocks, and a small piece an antler for shaping
smaller pieces. The antlers serve as a small hammer, and can be substituted with
a hard wood, such as oak, if antler is not readily available. You will also need
a hammer stone. This is essentially a blunt stone that is very dense. Granite
makes the best hammer stone, but basalt and quartz are also good options.
Find a piece of soft stone that is free from cracks or frost fractures. It
should be soft, but not brittle. This will allow you to chip away at the stone
in a process known as flaking. The best stone to use is flint. If flint is not
indigenous to your area, then chalcedony, chert, jasper, obsidian and quartzite
are also good stones to fashion into arrowheads.
Strike your flint, or whichever soft stone you are using, with your hammer
stone. Hit the stone hard enough to break off a piece that is small and
relatively flat. If the flake that breaks off is already the size of an
arrowhead then it is too small. You need a slightly larger piece that you can
work down to the proper shape. A flake of flint that is five to six times the
size of an arrowhead is ideal.
Use your large antler as a soft hammer to begin reducing the size of the stone.
Remember that even though antler works best, a chunk of hard wood, such as oak,
will also break flakes off of the stone. Strike the stone with the antler to
knock away flakes. The idea here is to make the stone thinner each time. The
overall size will also decrease as pieces are chipped away. Grind the hard
hammer stone over the edge of the flint each time a flake is broken away. This
will grind away any micro-fractures and prevent the stone from crushing on the
Switch to the smaller antler when the size of the flint begins to be reduced.
This will allow you to chip away smaller flake so that you do not ruin the
entire arrowhead by knocking off an excessively large flake. Strike the stone
with the small antler, and then grind the edge with the hammer stone, until the
flint is roughly the right shape and size to be an arrowhead.
Obtain an ishi stick. Traditional ishi sticks were a sturdy stick with a small
piece of bone or antler strapped to the tip. Modern ishi sticks can be purchased
that are made of hard rubber, with a fine metal tip. Refer to the "Flintknapping
Tools" link in the resources section to review a selection of ishi sticks that
are commercially available.
Use the ishi stick as a pressure flaker. Hold the flint, now in the rough shape of an arrowhead, in the palm of your hand. Firmly press the ishi stick into the side edge of the flint to break a small flake away. Continue breaking away small flakes all the way around the edge of the arrowhead. This will make the edge thinner than the body of the arrowhead, which makes the stone sharp. You now have a completed stone arrowhead.
Nature Bulletin No. 505-A November 3, 1973
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation