Kremer Pigmente GmbH & Co. KG     Kremer Pigments Inc., USA  

Chemical composition : CuCO₃.Cu(OH)₂

Malachite is perhaps the oldest known bright green pigment. It is the natural basic copper carbonate and is siilar in composition to the blue basic copper carbonate, azurite, except that it contains a greater amount of combined water. Like azurite it occurs in many parts of the world and is associated with secondary copper ore deposits.

Malachite was used in ancient Egypt for eye-paint as early as predynastic times and was found on Fourth Dynasty tomb paintings. Curiously, malachite was not used in paintings extensively as azurite in Europe. It is also less frequently mentioned in written sources. Malachite was found to be used extensivelyalong with azurite in Western Chinese paintings of the ninth to the tenth centuries. It was also reported on seventh- to eight-century Buddhist wall paintings in Japan.

Classical and medieval writings refer to malachite as "chrysocolla", a word derived from the Greek words for gold and glue because the ancients used it in soldering gold. The current term chrysocolla was given my mineralogists to the blue-green natural cryptocristalline hydrosilicate of copper (see chrysocolla). Malachite is prepared as a pigment by careful selection, grinding and sieving. In transmitted light coarse particles are dark green and fine particles are a pale green. If the particles are too finely ground it becomes too pale for practical use. Because malachite is produced by crushing and grinding, all the particles have a fractured appearance. Many larger particles have a fibrous structure and it is not uncommon to find particles of associated minerals such as azurite, chrysocolla and cuprite. Under the microscope malachite particles show a pale greenish colour by transmitted light.

Malachite is stable to light and normal atmosphere. Malachite has a moderately low refractive index, and is thus more satifactory in tempera and in an oil-medium.

Malachite is also suitable for the technique of true fresco. It is the most important green up until the 18^th century. Its properties are similar to azurite: it turns yellowish green in oil, is permanent in frescos when mixed up fresh with lime, and is suitable for tempera.