English noun: tourmaline | |||
| 1. | tourmaline (substance) 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 | ||
| Broader (hypernym) | mineral, transparent gem | ||
| Narrower (hyponym) | schorl | ||