tourmaline
英 ['tʊəməlɪn; -liːn]
美['tʊəməlɪn]
- n. [矿物] 电气石
英英释意
- 1. a mineral that is a complex borosilicate and hydroxide of aluminum containing iron and magnesium and calcium and lithium and sodium; it is usually black but occurs in transparent colored forms that are used as gemstones