Tourmaline (common colour name): In the diamond trade, the name tourmaline can be applied to pure pink (PK), brownish pink (br-PK), purplish pink (pp-PK), or brownish purplish pink (br-pp-PK) hues that exhibit pale or bright tones, or pure blue (B), pure green (G), olivish green (ol-G), or olive-green (OL-G) hues that exhibit dull or deep tones. On occasion the term tourmaline green appears in the gem literature with reference to treated coloured diamonds.