▁tri pol i , ▁is ▁fine ▁pow der ed ▁por ous ▁rock ▁used ▁as ▁a ▁pol ishing ▁ab ras ive ▁for ▁met als m ith ing ▁and ▁in ▁wood working . ▁It ▁is ▁usually ▁weather ed ▁lim estone ▁mixed ▁with ▁di atom ace ous , ▁am orph ous , ▁or ▁cry st all ine ▁sil ica . ▁It ▁has ▁similar ▁applications ▁to ▁p um ice , ▁but ▁it ▁is ▁generally ▁sold ▁as ▁a ▁fin er ▁pow der ▁and ▁used ▁for ▁a ▁more ▁gl oss y ▁pol ish ▁after ▁an ▁initial ▁treatment ▁with ▁co ar ser ▁p um ice ▁pow der . ▁Tri pol i ▁particles ▁are ▁rounded ▁rather ▁than ▁sharp , ▁making ▁it ▁a ▁mil der ▁ab ras ive . ▁ ▁It ▁is ▁usually ▁mixed ▁with ▁oil , ▁sometimes ▁water , ▁and ▁rub bed ▁on ▁the ▁surface ▁of ▁var n ished ▁or ▁lac quer ed ▁wood ▁with ▁a ▁felt ▁pad ▁or ▁cloth . ▁Rotten ▁stone ▁is ▁sometimes ▁used ▁to ▁buff ▁st ains ▁out ▁of ▁wood . ▁Some ▁pol ishing ▁w ax es ▁contain ▁pow der ed ▁ro tt en ▁stone ▁in ▁a ▁paste ▁substr ate . ▁For ▁larger ▁pol ishing ▁jobs , ▁ro tt en ▁stone ▁mixed ▁with ▁a ▁b inder ▁is ▁applied ▁to ▁pol ishing ▁whe els . ▁ ▁It ▁has ▁also ▁been ▁used ▁to ▁pol ish ▁br ass , ▁such ▁as ▁that ▁found ▁on ▁military ▁uniform s , ▁as ▁well ▁as ▁steel ▁and ▁other ▁met als . ▁Pl ates ▁used ▁in ▁dag uer re ot ypes ▁were ▁pol ished ▁using ▁ro