Is there such a thing as a waterstone and an oilstone? Are they different, or can a stone be used with either oil or water?
Carol Reed: Yes to the first and second question, and no to the third.
John Brock: Waterstones and oilstones refer to the solution that is used to float the debris off the stone left from sharpening. Waterstones are usually more friable, meaning that they wear faster, but fresh abrasive is exposed more quickly than most oil stones, so they usually cut the metal faster. There are people that swear by both. Each “system” has its own advantages and disadvantages. I have seen a few stones that advertise you can use them with oil or water. I have not found the performance of these stones to be nearly as good as their more specific cousins.