Malachite

see also: Etymology of Malachite

The malachite is a mineral carbonate of formula Cu₂ (CO₃) (OH) ₂, monoclinical, Groupe of space P 2₁/ has , which is formed in the zone of oxidation of sulfides of Cuivre, often associated with the azurite and the native Cuivre. The malachite can also be of orange color.

This stone is of an intense and vibrating color green, almost always microcrystalline. When is formed by oxidation of the Cuivre to the air, it takes the name of verdigris . It can also be red orange. It has a density from approximately 2,5 to 3 g/ml. It has a hardness from 3,5 to 4, which is rather fragile.

The name of this mineral comes from the Latin through the old Greek molochitis , stone of color mauve-green, molochē , alternative of malachē , " mauve". The malachite is used as mineral pigment since Antiquity to return some tons clear and luminous blue-greens, in particular in the painting of the icons. The pigment is sensitive to the light and the acids and tends to transfer color. Its natural form was replaced by a synthetic form, the Verditer.

The malachite is used like decorative stone, for columns, tables, jewels etc In Cosmétologie, it has a protective action on several levels of the antioxydant process of defense of the cells, and a detoxifier effect.

Toxicity

The green malachite is toxic. It is used with low dose as veterinary medicinal product, supported more or less well according to the species. Salmonidés support it particularly well, whereas the fish cat Ictalurus punctatus, is particularly sensitive there (possible disorders and possible death with the top of 0,1 ppm during one hour, when the trout supports 1 to 3 ppm during one hour). The green malachite used to treat fish must be free from zinc, the latter being very toxic for fish.

The layers are in the the Ural, in Democratic republic of Congo, with the Chile, in Namibia and Australia.

Quotation

Alphonse Allais often recalled that the malachite never profits .

Zh-yue: 石綠

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