Almost any type of lapidary rock can be polished. Polishing a stone requires that the stone be ground down using progressively finer grades of sandpaper or grit. This grinding is usually done with a fixed wheel grinder with sanding belts attached to a rotating wheel. There is usually a water source added so that the cutter does not breath in the dust. Once the stone is very smooth there are several types of polish and buffs that are used on different materials to give it a glossy finish. The buffs are also mounted on a rotating wheel. Some stones, such as common with Turquoise, must be "stabilized" or treated with a resin before they can be cut. Some stones, such as Rhyolite, are too porous and do not take a high gloss polish. Tiny stones are sometimes stuck on a wooden dow with wax to make them easier to manage. Rock tumblers are filled with grit and stones, then left to tumble for 21-30 days, slowing grinding away the stones until they are smooth. Extra large polished pieces can take a lot of time and effort, but they are unique and beautiful decorating rocks. Decorating with rocks is easy because rocks come in so many beautiful colors and patterns.