Knapping

Knapping is the shaping of flint, chert, obsidian or other conchoidal fracturing stone through the process of lithic reduction to manufacture stone tools, strikers for flintlock firearms, or to produce flat-faced stones for building or facing walls, and flushwork decoration. The original Germanic term "knopp" meant strike, shape, or work, so it could theoretically have referred equally well to making a statue or dice. Modern usage is more specific, referring almost exclusively to the hand-tool pressure-flaking process pictured.

Flintknapping or knapping is done in a variety of ways depending on the purpose of the final product. For stone tools and flintlock strikers, chert is worked using a fabricator such as a hammerstone to remove lithic flakes from a nucleus or core of tool stone. Stone tools can then be further refined using wood, bone, and antler tools to perform pressure flaking.

For building work a hammer or pick is used to split chert nodules supported on the lap. Often the chert nodule will be split in half to create two cherts with a flat circular face for use in walls constructed of lime. More sophisticated knapping is employed to produce almost perfect cubes which are used as bricks.

There are many different methods of shaping stone into useful tools. Early knappers could have used simple hammers made of wood or antler to shape stone tools. The factors that contribute to the knapping results are varied, but the EPA (exterior platform angle) indeed influences many attributes, such as length, thickness and termination of flakes.

Hard hammer techniques are used to remove large flakes of stone. Early knappers and hobbyists replicating their methods often use cobbles of very hard stone, such as quartzite. This technique can be used by flintknappers to remove broad flakes that can be made into smaller tools. This method of manufacture is believed to have been used to make some of the earliest stone tools ever found, some of which date from over 2 million years ago.

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Wikipedia