Another use of oxalic acid is in the finalpolishing of onyx, marble, and travertine.
另一种使用的草酸，是在最后的抛光玛瑙，大理石，和钙华。
2
Finalpolishing with the tools I mentioned before and, an agate knife. This is the pic shows half polished bracelet.
最后的抛光，这次的工具外加一把玛瑙刀，上图只抛光了左半边，对比明显。
3
The selection of the material, shaping and fine grinding of the substrate, and the polishing technologies are discussed in the paper. The final measuring results of the optical surface are given.