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
Malachite The mineral was given this name due to its resemblance to the leaves of the mallow plant. Malachite was extensively mined at the Great Orme mines in Britain 3,800 years ago using stone and bone tools. Archaeological evidence indicates that mining activity ended around 600 B.C.E with up to 1,760 tonnes of copper being produced from the mined Malachite. Archaeological evidence indicates that the mineral has been mined and smelted to obtain copper at Timna Valley in Israel for over 3,000 years. Since then, malachite has been used as both an ornamental stone and as a gemstone. In ancient Egypt