rottenstone

/rot-n-stohn/US // ˈrɒt nˌstoʊn //UK // (ˈrɒtənˌstəʊn) //

烂石,烂石头,腐石,烂石子

Definitions

n.名词 noun

1
- : a friable stone resulting from the decomposition of a siliceous limestone, used as a powder for polishing metals.

The unpainted surfaces will be kept clean and bright with rottenstone and oil or "Putz-pomade."
Polishing is effected by wooden wheels fed with wet pumice-powder and rottenstone and by brushes fed with moistened putty-powder.
Tripoli (and rottenstone) are used in polishing powders and scouring soaps as well as for filter blocks and many other purposes.