Editing Prismatic blade (section)

==Morphology==
[[Image:chunchucmil-obsidian.jpg|thumb|An obsidian prismatic blade fragment from [[Chunchucmil]], [[Yucatán (state)|Yucatán]], [[Mexico]]]]

Prismatic blades are often [[trapezoid]]al in cross section, but very close in appearance to an [[isosceles trapezoid]].  Triangular blades (in cross-section) are also common.  The ventral surface of the prismatic blade is very smooth, sometimes bearing slight rippling reflecting the direction of applied force and a very small [[bulb of applied force]] (indicative of pressure reduction).  Flake scars are absent on the ventral surface of these blades,  though [[Eraillure|eraillure flakes]] are sometimes present on the bulb.  The dorsal surface, on the other hand, exhibits scar ridges running parallel to the long axis of the blade.  These facets are created by the previous removal of blades from the core.  The proximal end contains the blade's [[striking platform]] and its bulb of applied force, while the distal end will consist of a snap break, a feather termination, or a stepped termination.