What is "malachite green"

Green \Green\ (gr[=e]n), n.

1. The color of growing plants; the color of the solar spectrum intermediate between the yellow and the blue.

2. A grassy plain or plat; a piece of ground covered with verdant herbage; as, the village green.

   O'er the smooth enameled green.
   --Milton.

3. Fresh leaves or branches of trees or other plants; wreaths; -- usually in the plural.

   In that soft season when descending showers Call forth the greens, and wake the rising flowers.
   --Pope.

4. pl. Leaves and stems of young plants, as spinach, beets, etc., which in their green state are boiled for food.

5. Any substance or pigment of a green color. Alkali green (Chem.), an alkali salt of a sulphonic acid derivative of a complex aniline dye, resembling emerald green; -- called also Helvetia green. Berlin green. (Chem.) See under Berlin. Brilliant green (Chem.), a complex aniline dye, resembling emerald green in composition. Brunswick green, an oxychloride of copper. Chrome green. See under Chrome. Emerald green. (Chem.)

   1. A complex basic derivative of aniline produced as a metallic, green crystalline substance, and used for dyeing silk, wool, and mordanted vegetable fiber a brilliant green; -- called also aldehyde green, acid green, malachite green, Victoria green, solid green, etc. It is usually found as a double chloride, with zinc chloride, or as an oxalate.

   2. See Paris green (below).

      Gaignet's green (Chem.) a green pigment employed by the French artist, Adrian Gusgnet, and consisting essentially of a basic hydrate of chromium.

      Methyl green (Chem.), an artificial rosaniline dyestuff, obtained as a green substance having a brilliant yellow luster; -- called also light-green.

      Mineral green. See under Mineral.

      Mountain green. See Green earth, under Green, a.

      Paris green (Chem.), a poisonous green powder, consisting of a mixture of several double salts of the acetate and arsenite of copper. It has found very extensive use as a pigment for wall paper, artificial flowers, etc., but particularly as an exterminator of insects, as the potato bug; -- called also Schweinfurth green, imperial green, Vienna green, emerald qreen, and mitis green.

      Scheele's green (Chem.), a green pigment, consisting essentially of a hydrous arsenite of copper; -- called also Swedish green. It may enter into various pigments called parrot green, pickel green, Brunswick green, nereid green, or emerald green.

n. (context organic compound English) A toxic chemical used as a dye, as a treatment for infections in fish (when diluted), and as a bacteriological stain.

Malachite green is an organic compound that is used as a dyestuff and controversially as an antimicrobial in aquaculture. Malachite green is traditionally used as a dye for materials such as silk, leather, and paper. Although called malachite green, this dye is not prepared from the mineral malachite - the name just comes from the similarity of color.