①An emerald is a precious stone which is clear and bright green.【n.翡翠;绿宝石】
②Something that is emerald is bright green in colour.【n.翠绿色;翡翠色】
①Flaws in emeralds greatly reduce their value.
②Her bracelet was set with emeralds .
Matt Haig的新书 The Midnight Library 也出现了这个表达：
speak for itself
If something speaks for itself, it is clearly so good or effective that no additional argument about it is necessary.
His success as a lawyer speaks for itself .
《经济学人》一篇题为 To feed the world 的文章也出现了这个表达：