Malachite Green
Description
A dark green synthetic organic dye that was named for the mineral because of its color hue. Malachite Green is an aniline based dyestuff (a triphenylmethane salt) made by Dobner and Fisher in 1877. Both the chloride and the oxalate salt are known by the same name. In a neutral aqueous solution, its green crystals give an absorption maximum at 616.9 nm. Malachite Green is used for the direct dying of silk, wool, jute, acrylic and leather. It is also used to dye cotton and paper after mordanting. Malachite Green can be used in spot chemical tests for the detection of sulfurous acid and cerium. It is used as an acid-base indicator with the following color ranges: yellow at pH 0, green at pH 2.0, cyan at pH 11.6, and colorless at pH 14. Malachite Green has previously been used to kill parasites, mold, and fungi in fish tanks, but is now banned or heavily regulated.
Synonyms and Related Terms
malachite green chloride; Basic Green 4; CI 42000; viktoriavihreä (Fin.); Viktoriagrün (Deut.); Braunschweigergrün (Deut.); vert malachite (Fr.); viktoriagrönt (Sven.); verde malaquite (Port.); benzaldehyde green; aniline green
Commercial names: Victoria Green B; China Green; Diamond Green B; Light Green N; Benzal Green; Fast Green
Risks
- Toxic by ingestion.
- Contact may cause irritation.
- Decomposes upon heating yielding toxic fumes of hydrogen chloride and nitrogen oxides
- Heavily regulated or banned for use in aquaculture due to its toxicity and potential carcinogenity
- Fisher Scientific: MSDS
Physical and Chemical Properties
- Soluble in water and ethanol, methanol and amyl alcohol.
- pH indicator: yellow below 0.2; green from 1.8 to 11.5; colorless above 13.2
- Composition = C23H25ClN2 (Chloride); C52H54N4O12 (Oxalate)
- CAS = 569-64-2(Chloride); 2437-29-8 (Oxalate)
- Molecular Weight = 364.92 (Chloride); (Oxalate)
Resources and Citations
- Wikipedia: Malachite Green Accessed April 2026
- Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
- The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 5739
- Encyclopedia Britannica, http://www.britannica.com Comment: "malachite green." Accessed 7 Apr. 2005.
- Website: www.straw.com/sig/dyehist
- Website: http://www.coloria.net/varita.htm - foreign language equivalent terms
- The Dictionary of Art, Grove's Dictionaries Inc., New York, 1996
- Colour Index International online at www.colour-index.org