Which material, found in chalk, was used to make prehistoric tools?

Flint is a hard, sedimentary cryptocrystalline form of silica, which can be found in chalk. Its characteristics make it an ideal material for prehistoric tool-making. Flint can be easily shaped and knapped, allowing early humans to produce sharp blades, points, and other cutting tools that were essential for survival in prehistoric times.

The use of flint in tool-making is well-documented in archaeological finds, as it could be fashioned into tools with effective cutting edges. Its abundance in certain environments, particularly in areas with chalk deposits, contributed to its popularity among prehistoric peoples.

Other materials listed, such as granite, obsidian, and basalt, are not typically associated with chalk. While granite is an igneous rock and not used for traditional tool-making in the same way as flint, obsidian is a naturally occurring volcanic glass known for its sharpness but is not found in chalk. Basalt, while a common stone in tool production, especially in some regions, does not share the same association with chalk as flint does. Thus, flint stands out as the correct answer to the question about prehistoric tool materials sourced from chalk.