Vermilion

#E34234Formula HgSEarliest recorded use c. 7000 BCE

19 eras40 artists62 colors

Vermilion is mercury sulphide: a brilliant, opaque, faintly orange scarlet that was the strongest red available to European painters for fifteen centuries, and that is poisonous enough that the people who made it rarely lived long.

Origin

The mineral form is cinnabar, and the great European source was the Almadén mine in Castile, worked since Roman times and for long stretches the largest mercury deposit on earth. Rome staffed it with convicts and slaves, which tells you what the work was like. From around the ninth century the pigment was also made synthetically: the alchemical dry process fused mercury and sulphur into black mercuric sulphide, which was then sublimated in a flask and condensed on the walls as red crystals — one of the earliest chemical syntheses in the European tradition, described in Arabic sources and passed to the West through the alchemical literature. Cennini warned painters to buy it whole rather than powdered, since ground vermilion was routinely adulterated with red lead, and to grind it themselves — "if you were to grind it for twenty years, it would only get better".

In art history

Before vermilion the reds available were earths: red ochre, burnt sienna, warm but dull. Vermilion is the first red in Western painting that genuinely shouts. It was the drapery red of the Middle Ages and the Renaissance, the red of a cardinal's robe in Raphael and of the lacquered accents in Titian, and it appears in seventeen separate eras in this collection. Painters typically pushed it further with a glaze of a red lake — madder or kermes — over the top: the vermilion supplies opacity and brilliance, the transparent lake supplies depth, and the combination gives the glowing crimson of a Venetian mantle that neither pigment achieves alone. In Chinese and Japanese practice the same mineral gives the red of lacquer and of seal ink, where it has been used continuously for millennia.

In the studio

Vermilion has one notorious failing. Exposed to light — particularly in the presence of chlorides — it can convert to metacinnabar, a black form of the same compound, and the red turns purple-black in patches. The effect is unpredictable: two paintings from the same workshop can behave completely differently, and a single passage can darken while the vermilion beside it stays brilliant. Medieval treatises already warn about it. It is why some Sienese panels have blackened robes, and why painters increasingly protected their vermilion under a varnish or a lake glaze. In oil it is otherwise well-behaved and dries at a moderate rate; in fresco it was avoided in favour of red ochre, which is inert.

Afterlife

Cadmium red, introduced commercially around 1910, offered a comparable brilliance without the mercury and without the darkening, and it displaced vermilion almost completely within a generation. The transition is legible in this database: the eras after 1910 use cadmium where the earlier ones use vermilion, and in several cases the two sit side by side as a workshop changed over. Genuine vermilion is still manufactured in small quantities, mostly for conservation and for East Asian lacquer and seal work, and it remains classified as acutely toxic.