diamond

1.diamond统指“金刚石”。a diamond是“一块金刚石”。diamonds是“多块金刚石”。

2.diamond cut diamond是习语，作“针锋相对”或“棋逢敌手”解。全语用作名词，如Whenever he argues with his brother, it is diamond cut diamond。cut是动词，习惯用cut而不用cuts或cutting。