Malachite the mineral is basic carbonate of copper, usually described as a bright greenish blue or sometimes as pale green. Our malachite is from mines in Nizhniy Tagil, Ural Mountains, Russia in a medium grade of dark green.
Current Names: German: Malachit; French: malachite; Spanish: malaquita; Italian: malachito Obsolete Names: English: chrysocolla, Hungarian green, mineral green, mountain green; German: Berggruen, Malachitgruen; French: vert de montagne; Italian: verde minerale. Alternate Names: It is also known as copper green, green bice, and green verditer, although these names are usually given to the artificial pigment. Color: Blue-Green Colour Index: Pigment Green 39 (77492) ASTM Lightfastness: Oil: I Acrylic: I Watercolor: I Density: 4 Hardness: 3.5 to 4 Chemical Formula: CuCO3.Cu(OH)2
Malachite the mineral is basic carbonate of copper, usually described as a bright greenish blue or sometimes as a pale green. Our malachite is obtained from mines in Nizhniy Tagil, Ural Mountains, Russia.
History of Use: It is an historical pigment having been found in Egyptian tomb paintings as early as the Fourth Dynasty (sixth century B.C.). It received sparse mention in medieval literature probably because it is more commonly found in egg tempera paintings than in European oil-resin easel paintings, and it was often associated with azurite.
Grades: Available from Iconofile in two grades or fineness of grind; fine and medium, which produce corresponding light and dark tones of green when used in aqueous medium.
Permanence and Compatibility: Malachite is moderately permanent. It is unaffected by exposure to light. It is said to be incompatible with sulfide pigments, such as cadmium yellow, orpiment, realgar ultramarine, and vermilion. Even though theoretically subject to blackening when mixed with sulfide pigments, in practice this has never been reported. Malachite areas on Italian frescoes are often still bright green.
Oil Absorption and Grinding: No data has been published on the oil absorption properties of malachite. To be useful as a bright green it must be ground relatively coarse, because, if too finely ground, it becomes too pale for practical use. Cennino Cennini remarks that "if you were to grind it too much, it would come out a dingy and ashy color." He recommends grinding it in water; and "when you have got it worked up, put it into the dish; put some clear water over the color, and stir the water up well with the color. Then let it stand for the space of one hour, or two or three; and pour off the water; and the green will be more beautiful. And wash it this way two or three times, and it will be still more beautiful." Being moderately low in refractive index, it may be more useful in aqueous medium, such as tempera, than in oil-medium.
Toxicity: Malachite is moderately toxic and care should be used in handling the dry powder pigment to avoid inhaling the dust.
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