每日雅思词汇:常见的首饰表达 gold遥金; white gold白金; alloy合金; palladium钯金; titanium钛金; platinum铂金; silver白银; purity遥金纯度; Karat=K遥金的纯度单位; sterling silver纯银; diamond钻石; carat克拉; amber琥珀; amethyst紫水晶; sapphire蓝宝石; ruby红宝石