Malachite
Azurite's green twin — the same copper carbonate family, found in the same deposits, prepared the same way, and behaving according to the same rules. Where azurite is the old blue, malachite is the old green.
Origin
A basic copper carbonate mined from the weathered upper zones of copper ore bodies, malachite is one of the most visually distinctive minerals there is, banded in concentric rings of light and dark green. It was used as an eye cosmetic in Predynastic Egypt before it was ever a paint, and as a pigment it requires the same treatment as azurite: coarse grinding, because fine grinding turns it pale and chalky, and therefore a binder with enough body to carry large particles. Major sources included Sinai and the Eastern Desert for Egypt, the Urals for Russia, and deposits across central Europe and Asia.
In art history
Malachite is the standard green of Egyptian painting, of Chinese and Japanese painting — where it is called rokushō and graded by particle size like its blue counterpart — and of Byzantine and medieval European work. It appears in three eras here, all early and all outside the modern Western mainstream, which reflects its history accurately: in Europe it was substantially displaced by verdigris, which is far more brilliant, while in East Asia it remained a principal green into the modern period because the aesthetic there valued its matte, mineral, granular surface rather than treating it as a deficiency.
In the studio
Its behaviour follows directly from being a coarse mineral. It is semi-opaque, moderately weak, granular, and does not glaze — it sits as a body of colour with a visible texture. It is lightfast and stable in glue and gum media, which is where East Asian painting uses it, but it darkens in oil, and like all copper pigments it is incompatible with sulphur-bearing colours and vulnerable to acids. It is safe in fresco only with care, since it can be attacked by fresh lime.
Afterlife
Displaced in Europe by verdigris and then by the synthetic greens of the nineteenth century, malachite survives in East Asian painting, in conservation, and in Russian decorative art, where the banded stone itself — rather than the ground pigment — was used for columns, tabletops and entire rooms, most famously the Malachite Room of the Winter Palace.
Where it appears
Every era and artist in this atlas whose palette includes this pigment.