Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

Abrader

A stone used to sand sharp edges, often for strengthening platforms. Abraders are often made of sandstone.

Abrading platforms

In order to produce longer flakes and reduce shatter, the knapper will sand the edge of the nucleus so that the platform is not too thin or weak.

Antler billet

A type of soft hammer. The antler billet comes from the section of antler that attaches to the skull.

Anvil

A stone on which the knapper holds the nucleus to split it during bipolar flaking

B

Biface thinning flake

A flake that crosses at least halfway across the nucleus. The knapper makes biface thinning flakes in order to transform the nucleus into a sharp, narrow biface.

Bifacial tool

A knapper removes flakes from both faces of a bifacial tool. Projectile points are bifacial tools.

Bipolar flakes

When knappers only have round nodules of knappable material that lack platforms of less than 90°, they often use bipolar flaking to split the nodules. In bipolar flaking, the knapper places the nodule on an anvil and breaks it with a hammer stone. The force of the anvil and hammer stone produce tight, concentric rings at platforms at both ends of the flake.

Bipolar flaking

Knappers use bipolar flaking for toolstone nodules that lack a platform of less than 90° (e.g. round nodule). The knapper places the nodule on an anvil and breaks it with a hammer stone. The force of the anvil and hammer stone produce tight, concentric rings at platforms at both ends of the flake.

Bulb of percussion

A round mound just beneath the platform of a flake. It is part of the Hertzian cone.

Burin spall

The knapper removes the straight edge of a biface to make a burin spall. Burin spalls can be made into drills.

C

Chaîne opératoire

The operational sequence of making, using, and discarding tools. The step-by-step decisions include acquiring raw materials, making a tool, using the tool, and discarding the tool. Understanding these decisions helps us understand the lives of past people.

Compression waves

Ripples radiating from the point of impact on the platform of a flake (much like ripples in a pond radiate out from the point where a stone hits the water)

Conchoidal fracture

The typical fracture pattern of knappable toolstone. The fracture pattern resembles the growth rings of a bivalve shell.

Cone of percussion

When the knapper applies percussive force to the nucleus, the conchoidal fracture propagates in a cone from the point of impact. This cone of percussion is also known as the Hertzian Cone.

Cortex

Naturally weathered rind of unknapped toolstone. The first flakes that the knapper strikes from a raw nucleus have cortex on the dorsal face. The finishing flakes usually have little or no cortex.

D

Debitage

Waste products from the tool-making process. (Debitage comes from the French word for trash.) The most common lithics in the archaeological record are debitage, not tools.

Distal end

The termination of the flake opposite the platform.

Dorsal face

The side of a flake that faces away from the nucleus when the flake is refitted into the nucleus

E

End shock

A bending break in the middle of the workpiece that occurs when the knapper didn't properly support the piece during knapping. End shock often occurs when the middle of the workpiece is thinner than the ends.

Erraillure scar

Often removing a flake from the nucleus produces a secondary flake. The erraillure scar is the flake scar from this secondary flake. The errailure scar is close to the platform.

F

Face

A side of a nucleus, flake, or tool. Flaked stone tools are often classified by the number of faces that the knapper has flaked. (See Unifacial and Bifacial definitions.)

Feather termination

The distal end of the flake thins to sharp edge. Usually the knapper wants a feather termination to make sharp tools.

Fissures/hackles

Lines like a sunburst from the point of impact on a flake. They point to the platform.

Flake

Section of stone removed from a nucleus through percussion or pressure.

Flake scar

Place on the nucleus where the flake refits

Flaked/chipped stone technology

Stone tool technology that involves flaking stone through percussion or pressure. It is used to make tools such as knives, projectile points (spear and arrow points), scrapers, and drills.

Flintknapping

The process of making stone tools. Flintknapping often refers specifically making flaked stone tools.

G

Groundstone technology

Stone tool technology that involves shaping stone through abrading, polishing or pecking. It is used to make tools such as manos, metates, mortars, pestles, bowls, and axes.

H

Hackles

See Fissures.

Hammer stone

A stone that the knapper uses to strike the nucleus to remove flakes. The knapper chooses the hardness and weight of the hammer stone based on material to be knapped. Archaeologists identify hammer stones based on their use wear. A well-used hammer stone has a lot of nicks and scratches that tend to be concentrated on certain areas of the stone instead of evenly distributed.

Hard hammer percussion

The knapper strikes the nucleus with a stone (hard) hammer to remove flakes. Hard hammer percussion tends to produce a large bulb of percussion on flakes.

Hertzian cone

See Cone of percussion.

Hinge termination

The distal end of the flake is thick and rounded because the knapper did not strike the platform with enough force to feather out. Usually the knapper is disappointed to make a hinge termination because the flake isn't sharp and the flake scar makes it harder to strike flakes with feather terminations from the nucleus.

I

Isotropic

Fractures the same, predictable way in all directions. Good toolstone is isotropic.

J

K

L

Lip

Soft hammer percussion often produces a small lip under the platform. The lip is easier to identify by touch than by sight.

Lithics

Stone tools and the waste products of the tool-making process

M

Margin

Edge of the nucleus where the faces meet. The knapper will raise or lower the margin depending on where they strike off a flake.

N

Nucleus

Toolstone nodule from which the knapper removes flakes. Sometimes the knapper shapes the nucleus into a tool. A core is a type of nucleus that the knapper has shaped to remove specific types of flakes.

O

Overshoot termination

The flake extends across the nucleus and removes the margin (edge) opposite the platform. The knapper struck the platform with too much force to feather out. Some knappers intentionally strike overshot flakes to make the nucleus more narrow.

P

Platform

Where the flake is struck from the nucleus (i.e., the spot where the percussive or pressure force is applied). A platform must have an angle less than 90°.

Pressure flake

Knappers make pressure flakes by using an antler or copper tool to build up force on the edge the nucleus. They then change the angle of the force to initiate material failure and remove the flake. Knappers make pressure flakes to sharpen the edges of bifaces and create notches for projectile points. Pressure flakes are often too small to be caught in the screens used in archaeological excavations.

Pressure flaker

A tool usually made of an antler tine or copper that the knapper uses to remove pressure flakes. Knappers press the pressure flaker on the edge the nucleus. They then change the angle of the force to initiate material failure and remove the flake.

Pressure Flaking

During pressure flaking, knappers use an antler or copper tool to build up force on the edge the nucleus. They then change the angle of the force to initiate material failure and remove the flake. Knappers make pressure flakes to sharpen the edges of bifaces and create notches for projectile points.

Proximal end

The end of the flake where the knapper had struck the platform. The platform is always located at the proximal end.

Q

R

S

Soft hammer percussion

Knappers traditionally use hardwood or antler billets as soft hammers. Soft hammers initiate a bending break in the toolstone. Soft hammer percussion typically results in a smaller bulb of percussion than hard hammer percussion. Soft hammer percussion often produces a small lip under the platform of a flake. The lip is easier to identify by touch than by sight.

Square margin

An edge of a nucleus that is at least 90°. Since a square margin does not have a platform where the angle is less than 90°, the knapper uses alternate flaking starting at one corner of the square margin. The flake scar of this first flake provides the platform for the next flake. The knapper makes alternate flakes working across the margin to produce a bifacial edge.

Step termination

The distal end of the flake is thick and squared because the knapper did not strike the platform with enough force to feather out. Instead, the break abruptly veers up at distal end of flake. The square angles of the step that is left on the nucleus will cause step terminations in subsequent neighboring flakes, causing a big headache for the knapper.

T

Termination

The end of a flake that is located opposite the platform (i.e., the distal end of the flake). The different types of terminations depend on the angle and strength of force that the knapper used to remove the flake. (See Feather termination, Hinge termination, Overshoot termination, and Step termination.)

Toolstone

Knappable raw material. Good toolstone is typically homogenous with a high silica content and cryptocrystaline structure.

U

Unifacial tool

A knapper removes flakes from just one face of a unifacial tool. Scrapers are typically unifacial tools.

Use wear

Evidence that part of an artifact has been used repeatedly. Use wear includes nicks and scratches on hammer stones and the dulling of the sharp edges of a cutting tool.

V

Ventral face

The side of a flake that fits into the nucleus when the flake is refitted into the nucleus