What is oil stone,how many types oil stone do you know?

Oil stone is a type of stripe shape bonded abrasives, Which is made of abrasive grains and bond. It's name was called because user’s usually use oil as Lubricant [ˈlubrɪkənt]. How many types of oil stones do you know? It can be divided into two types Artificial stone and natural stone. Artificial stone has [...]