(e.g. glauconite [greenish mineral]) Gr. kyanos = dark blue (e.g. cyanosis [blue skin/mucous membrane coloration due to lack of oxygen], cyanide [derived from the dye Prussian blue ], pyocyanine [blue toxin produced by the bacterium Pseudomonas aeruginosa ]) L. phoeniceus = purple-red [refers to the Phoenicians , who traded precious purple dyes