A black emery stone millstone is a type of millstone made from black emery stone, which is a hard and durable material used for grinding grains into flour. Millstones have been used for centuries in traditional grain mills to grind wheat, corn, and other grains into flour. The black emery stone millstone is known for its ability to produce fine flour due to the hard and abrasive nature of the emery stone. The rough surface of the stone helps break down the grains effectively, resulting in a finer texture of flour compared to other types of millstones. This makes it ideal for producing high-quality flour. This is a 18 inches (450 mm) black emery stone for the 10HP Flour mill/Atta Chakki.