Abrasive materials are substances used to wear away the surface of other materials through friction. Common examples include sandpaper, grit, and diamond dust. These materials are essential in various industries for tasks like cutting, grinding, and polishing, helping to shape and finish products. Abrasives can be classified into two main categories: natural and synthetic. Natural abrasives, such as quartz and emery, are sourced from the earth, while synthetic abrasives, like alumina and silicon carbide, are manufactured in laboratories. Each type has specific applications depending on the hardness and durability required for the job.