View more great items Abrasive Grit Kit for Rotary Rock Tumbler Polisher (4 Different Grit, Variety Pack) Get a Smooth, Polished Finish on Rocks, Semi-Precious Stones, Glass even Metals [Please see my other listings for both a single and a dual drum rock tumbler to use with the polishing grit] ---------- Note: Some Types of Rocks to Avoid A few types of igneous and metamorphic rocks are not good choices for the rock tumbler. These include: Schist, gneiss and other rocks that contain significant amounts of mica (micaceous rocks often split apart, shedding grains that spoil a polish) Rocks that are made up of easily dislodged grains (these dislodged grains will get into the polishing step and cause lots of scratches) Rocks such as scoria, pumice or vesicular basalt that contain open pore spaces (grit gets trapped in the pores and falls out during the next tumbling step, causing scratches on the rocks) Tuff and other poorly lithified rocks (as described above, these shed grains that spoil a polish) ---------- Fast Free Shipping, Next Day Processing (no waiting 2 months for your items to arrive from China) We strive to provide excellent service and on time deliveries, with either same day, or next business day Handling on all of our items.