rottenstone

名词 rottenstone:

1. a weathered and decomposed siliceous limestone; in powdered form it is used in polishing
   同义词：tripoli

rot.ten.stone

n.（名词）
A soft, decomposed limestone, used in powder form as a polishing material.
擦光石：一种粉末可作磨光材料的柔软的风化石灰石