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Make
an Arrowhead
| Flintknapping
is the making of flaked
or chipped stone tools. This technology was used in historic times to
manufacture
gun flints and in prehistoric times to make spear and dart points,
arrow
heads, knives, scrapers, blades, gravers, perforators, and many other
tools. |
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| Flintknapping
requires the ability to
control the way rocks break when they are struck. The best rock is
somewhat
brittle and uniform in texture and structure, lacking frost fractures,
inclusions, or other flaws. This type of rock is very fine grained or
non-grained.
The best rocks for flint-knapping are chert, flint, chalcedony,
quartzite,
jasper, and obsidian. These rock types, when struck with another rock,
piece of antler, or bone, will fracture or break in a characteristic
pattern
called a conchoidal fracture. This creates a rock fragment called a
flake. |
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| The
production process begins with a piece
of raw material, called a core. Flakes are removed by striking the edge
of the core with a sharp, forceful blow, in what is called percussion
flaking. |
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| Percussion
flakes are removed using a
hard hammer or soft hammer. Hard hammers are typically made of igneous
or metamorphic rocks such as granite, quartz, basalt, or gneiss. Hard
hammers
tend to pass most of their energy to the core without absorbing much of
the force, so they are used to flake large cores of hard materials. A
carefully
controlled strike is always more important than a hard strike when
using
a hard hammer. |
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| A soft
hammer is made of a piece of antler,
although bone and some very hard woods can be used. Moose, deer, elk,
and
caribou antler are all usable soft hammers. Soft hammers are used when
flaking very brittle material such as obsidian or when greater control
is needed. Soft hammers will not pass as much energy to the core and
will
absorb some of the force, affording greater control of the size and
shape
of the removed flake. Edges being worked must be ground dull prior to
flake
removal. This dulling helps prevent edge collapse. A piece of
sandstone,
very soft limestone, or other soft rock may be used to dull the edge. |
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| Indirect
percussion flaking is a process
where some device holds the core or flake being worked, leaving both
hands
free to drive off flakes with greater force or precision. One hand
holds
a punch-like piece of antler or bone against the core while the other
holds
a hammer and strikes the punch to drive off flakes. This combines the
accuracy
of pressure flaking with the force of percussion flaking. |
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| Another
method of flake removal is pressure
flaking. The knapper detaches flakes by applying leverage (pressure) to
an edge. An antler tine, piece of bone, or hard wood sharpened for
accurate
application of force is needed for flake removal. Downward and outward
pressure pops the flakes off. This method can straighten and sharpen
edges
of a finished tool or shape a tool from flake to final form. |
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| Heat
treatment improves the knapping quality
of some raw materials. It requires gradual application of high heat.
The
color and luster of the rock often change noticeably, and the flaking
quality
of the rock improves because its texture becomes smoother and less
grainy.
Heat treatment is usually applied to small and medium cores, flakes, or
bifaces; larger pieces are difficult to heat evenly and thoroughly. To
begin the process, a good sized fire is burned down to glowing coals
and
hot sand. A pit is excavated and the remains of the old fire placed
into
it (A and B). Already warmed chert pieces are placed into the pit (C)
and
covered with sand. A new fire is built and allowed to burn out over a
24
hour period before digging up the heat treated pieces. Care must be
taken,
for heat treatment can cause rocks to fracture explosively. |
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Source:
Office
of the State Archaeologist
700
Clinton Street Building
The
University of Iowa
Iowa
City, Iowa 52242-1030
|
American
Flintknappers
Most
knappers know full
well that their craft has little practical application in today's
world;
it is a craft performed for its own sake. Knappers find beauty and
inspiration
in stone, in prehistoric artifacts, and in the knapped art they make.
Making
Native American Hunting, Fighting, and
Survival Tools
Early
Hunting Tools
An
Introduction to Flintknapping
Flintknapping
Making and Understanding Stone Tools
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