Any piece of stone removed from a larger mass by the application of force, either intentionally, accidentally, or by nature. A portion of isotropic (homogenous) material having a striking platform and bulb of force (or bulb of percussion) at the proximal end. The flake may be of any size or dimension, depending on which technique was used for detachment (Crabtree 1982, 36).
A fragment of hard rock intentionally detached from:

- a core in the course of preparing or rejuvenating it
- which is then called a core preparation or core rejuvenation flake
a core with the intention of later turning it into a tool by retouch it:
- a tool in the course of shaping it by retouch: then called a retouched flake (Crabtree 1982. 14).


Flakes have two faces: a dorsal and a ventral. The dorsal surface can be partly or totally covered by cortex, but normally shows the scars from removals which were made before this flake was removed from the core.


The ventral surface contains only the features related to the detachment of this particular flake.

flake
Flakes also have two ends: a proximal and a distal. The proximal end contains the features of the point of impact and detachment or the point of percussion. Opposite this is the distal end.

Flakes and blades are oriented with the dorsal surface up and the proximal end (which can only be determined from the ventral surface) down. The left and right edges of the artifact are set from this orientation and remain as such, regardless of which way the piece is turned.
It is common for the dorsal surface to bear traces of negative scars from previous removals. These are called dorsal scars and are separated by a ridge which is created at the junction between two removals.

The ventral surface contains virtually all information pertaining to the detachment of this particular artifact from the core. The small section of platform retained from the core is now called the butt. The main surface of this face shows a swelling, or bulb, arising from a point just below the striking platform or point of percussion. Other features include concentric ripples, or lines of force, which show the direction of percussion, and irregular straight fissures, both of which radiate from the point of percussion.

A particularly important feature which can occur on the ventral surface is the bulbar scar, or érrailure. This is a small negative (concave) scar of irregular shape on the bulb marking the place from which a small chip springs away at fracture. As this feature is very common on humanly struck materials and is rare on naturally produced flakes it is a useful guideline to use when examining stray specimens which could be natural (see Patterson 1983, 300).

struckflake

see movie on the features of a struck flake