Malachite green metabolized into LMG. Only the cation MG is deeply colored, whereas the leuco and alcohol derivatives are not. This difference arises because only the cationic form has extended pi-delocalization, which allows the molecule to absorb visible light. The leuco form of malachite green was first prepared by Hermann Fischer in 1877 by condensing benzaldehyde and dimethylaniline in the molecular ratio 1:2 in the presence of sulfuric acid. Malachite green is traditionally used as a dye. Kilotonnes of MG and related triarylmethane dyes are produced annually for this purpose. MG is active against the oomycete "Saprolegnia", which infects fish eggs in
The Malachite Box Fairy Tale" (), based on "The Mistress of the Copper Mountain". Based on "Marko's Hill", Klara Katsman created the operetta "Mark Beregovik" (), which premiered in Sverdlovsk in 1955. Lyubov Nikolskaya composed the children's opera "Silver Hoof" based on the story of the same name in 1959. Vladimir Goryachikh composed the ballet "The Living Stone" () based on "Sinyushka's Well", which premiered in Nizhny Tagil in 1965. The 1973 opera "The Fire Maid" (based on "The Fire-Fairy") for schools was composed by Robert Long, with story adapted and lyrics by Dorothy Gulliver The 2012 opera "The Malachite Casket", based on