Malachite green (pigment)

A synthetic organic dye that is an aniline based dyestuff (a triphenylmethane salt) named for the mineral malachite because of its green color. It was first made by Dobner and Fisher in 1877. It is used for the direct dying of silk, wool, jute, and leather, to dye cotton after mordanting, in spot chemical tests for the detection of sulfurous acid and cerium, as an acid-base indicator, and to kill parasites, mold, and fungi in fish tanks.