A black emery stone millstone is a type of millstone built of black emery stone, a hard and robust material used to crush grains into flour. Wheat, corn, and other grains have been ground into flour in traditional grain mills for generations using millstones. The black emery stone millstone is recognized for grinding grains into fine flour due to its hard and abrasive character. The stone's rough surface aids in the effective breakdown of grains, resulting in a finer flour texture than other varieties of millstones. This is a 14 inches (350 mm) black emery stone for the 3HP Flour mill/Atta Chakki.