More profession-relevant items: sanding agents for wood and/or metal. Above and beyond plain old sand, that is.
scouring rushes (dried) -- can be used fresh but probably wouldn't be sold that way; moderate grit
sharkskin / dogfish skin -- moderate grit
pumice -- usually powdered for use; fine grit
rottenstone -- decomposed limestone and silica, also powdered, very fine; used for polishing
Thank you!