A microlith is a small stone flake, less than ca. 30 mm long, that was mounted onto a shaft or handle. The sharp, exposed edge of the microlith was the cutting element.
Microliths were mounted individually or were arranged in a line to provide a long edge. They were used as armatures on arrows or darts, or were the cutting edge for knives. By using small microliths in composite tools, the repair-kit did not require large stones. Microlith technology was independently invented in many different times and places, and archaeologists have developed elaborate typologies to describe these small stone tools. The earliest microliths are from the Howiesons Poort period in South Africa, ca. 60,000 BP, and they are an early example of technological innovation in our species.
‘Backed’ microliths are small blades or flakes that have been steeply trimmed on one edge. The opposite edge, called the chord, is left sharp and unmodified. The technique of steep trimming is called backing, in the sense that trimming creates a ‘back’ opposite the sharp working edge. Often backing was accomplished by supporting the microlith on an anvil during trimming, which creates a steep, nearly 90 degree edge. Special core reduction techniques were invented to produce the blanks for microliths.