Like Dremel grinding stones ? oxy stones for fish tanks ?
I’m not sure about the dremel bit, it’s a light abrasive, so it’s used in stuff like polishes, toothpaste, facial scrubs, nail files, etc.
For aquariums, they are not used like oxy stones, but as landscaping (aquascaping?). They’ve got to be treated first to remove the oxygen pockets, so they don’t float, but they are lightweight and very porous, so they don’t put pressure on the tank and they can host lots of bacteria.