Bulb Of Percussion

In flint-making, a swelling or bulb left on the surface of a blade or flake directly below the point of impact on the striking platform. In other words, a swelling on a flake or blade at the point where it has been struck to detach it from a core. On the flake or blade struck off there is a rounded, slightly convex shape around this point called the bulb of percussion and on the core there is a corresponding concave bulb. The point and the bulb of percussion are rarely present if a flake has been struck off naturally, as by heat or frost. Thus the presence of a bulb of percussion makes it possible to distinguish human workmanship from natural breakage.

When a flake is removed from a core by striking with a hammer, the flake has a swelling adjacent to the point where it was hit, and spreading over part of the newly exposed flake surface. This is called the bulb of percussion and usually indicates human manufacture.

İn flintmaking, a swelling or bulb left on the surface of a blade or flake directly below the point of impact on the striking platform - that is, a swelling on a flake or blade at the point where it has been struck to detach it from a core. On the flake or blade struck off there is a rounded, slightly convex shape around this point called the bulb of percussion and on the core there is a corresponding concave bulb. The point and the bulb of percussion are rarely present if a flake has been struck off naturally, as by heat or frost. Thus the presence of a bulb of percussion makes it possible to distinguish human workmanship from natural breakage. [bulb, bulb of force]