The blue worth its weight in gold: The secret epic of ultramarine
Imagine Venice at dusk in the fifteenth century. The canals shimmer beneath the flicker of torches, while a Genoese merchant, his fingers still stained with blue dust, haggles fiercely with a Venetian emissary. In his chests, wrapped in damask silk, lie fragments of stone from the farthest reaches o
By Artedusa
••10 min read
The blue worth its weight in gold: the secret epic of ultramarine
Imagine Venice at dusk in the fifteenth century. The canals shimmer beneath the flicker of torches, while a Genoese merchant, his fingers still stained with blue dust, haggles fiercely with a Venetian emissary. In his chests, wrapped in damask silk, lie fragments of stone from the farthest reaches of the known world—pieces of lapis lazuli torn from the Afghan mountains, more precious than gold, more coveted than the spices of the Indies. You have encountered this blue a thousand times without knowing it: in the Virgin’s mantle in the Sistine Madonna, in the turbulent skies of The Starry Night, in the turban of Girl with a Pearl Earring. But did you know that this pigment, ultramarine, shaped the history of art like few other materials? That it dictated the commissions of popes, ruined artists’ workshops, and even influenced Christian theology?
This is not just any blue. It is an obsession, a quest, a curse. And its story begins long before brushes ever touched it.
The cursed mines of Badakhshan
Deep in the Afghan mountains, where the Hindu Kush pierces the clouds like a blade, the earth’s bowels yawn open. Since the seventh millennium BCE, men have climbed the cliff faces by the light of oil lamps to extract a stone with celestial reflections: lapis lazuli. The miners of Sar-e-Sang—often children or slaves—work in galleries so narrow no one can stand upright. The air is thick with silica dust, which eats away at their lungs. Many die young, their eyes burned by the brilliance of the crystals, their fingers reduced to shreds.
Why so much suffering for a stone? Because lapis lazuli is no ordinary mineral. It is a geological miracle: a blend of lazurite, calcite, and pyrite that, once ground to powder, gives birth to ultramarine—this deep, almost electric blue that seems to capture light rather than reflect it. The Egyptians used it to adorn the sarcophagi of pharaohs; the Sumerians inlaid their divine statues with it. But it was in Europe, from the twelfth century onward, that this pigment became a currency more stable than gold.
Caravans took years to transport the stones from Afghanistan to Venice, via Persia and Constantinople. Each stage was an ordeal: bandits lay in wait, customs officials took their cut, ships sank. Upon arrival, a single kilo of lapis lazuli could cost the equivalent of a bourgeois house. And that was only the beginning of the journey.
Venetian alchemy: when stone becomes color
If Venice ruled the ultramarine trade, it was because it had perfected the art of transforming it. In the workshops of the speziari—apothecaries who were also color merchants—artisans spent weeks grinding, washing, and purifying the stone to extract the precious pigment. The process verged on black magic.
First, the lapis was crushed in porphyry mortars, a rock so hard it would not contaminate the color. Then came the crucial step: separation. The powder was mixed with wax, resin, and oil, then kneaded at length in a lye solution. The impurities—white calcite, golden pyrite—rose to the surface, leaving behind a blue sediment, nearly pure. This residue was ultramarine. But beware: from ten kilos of lapis, barely three hundred grams of pigment could be recovered. The rest? Worthless dust.
The best workshops, like that of the Vivarini brothers, guarded their secrets jealously. It was whispered that they added honey to soften the hue or bone powder to fix it. Some cheated, mixing ultramarine with indigo or smalt—a cheap cobalt blue that turned gray with time. Artists knew this and were wary. When the Duke of Milan, Ludovico Sforza, commissioned The Last Supper from Leonardo da Vinci, he stipulated in the contract that Christ’s mantle be painted with ultramarine "of the finest quality, without adulteration."
For once applied to the canvas, this blue must not lie. It had to shine like a fragment of heaven.
The Virgin’s mantle: when blue became sacred
In medieval Europe, color was never neutral. And blue, especially, carried the weight of the divine. Before the mass arrival of ultramarine, artists used azurite, a cheaper mineral pigment that turned green over time. Imagine the Virgin Mary, her mantle fading to verdigris like a bronze statue left in the rain. Heresy.
Ultramarine changed everything. Its stability made it the only blue worthy of representing the sacred. In the illuminations of the Très Riches Heures du Duc de Berry, angels wore robes of such intense blue they seemed to radiate. At Chartres, the stained glass of Notre-Dame de la Belle Verrière captured sunlight and returned it in a celestial hue. And in Florence, Giotto dared to paint the vault of the Scrovegni Chapel in pure ultramarine, as if the sky itself had been brought down to earth.
But this blue came at a price. Literally. In 1437, the painter Cennino Cennini noted in his Libro dell’Arte that ultramarine was worth "ten times its weight in gold." Artists used it sparingly, like a jewel. In The Virgin of the Rocks, Leonardo da Vinci reserved ultramarine for Mary’s mantle, while the other figures wore cheaper blues. Michelangelo, in a letter to Pope Julius II, complained: "Your Holiness asks me to economize on blue, but how am I to paint the sky without it?"
For patrons, ultramarine was an investment. The more a work contained, the more prestigious it was. Contracts from the period often specified the quantity and quality of pigment to be used. One telling detail: in Raphael’s The Marriage of the Virgin, Mary’s mantle is painted with pure ultramarine, while Joseph’s, as a mere mortal, is in azurite. The message was clear: the sacred had a price.
The masters’ tricks: when art deceives the eye
Not all artists could afford ultramarine. So they cheated. Brilliantly.
Jan van Eyck, master of illusion, layered glazes to create the impression of deep blue while using only a tiny amount of pigment. In The Virgin of Chancellor Rolin, Mary’s mantle appears bathed in light, yet in reality, Van Eyck first painted a dark background, then applied successive layers of transparent blue. The result? A depth that defies analysis.
Others, like Titian, mixed ultramarine with lead white to create lighter shades or used scumbling—a technique of applying dry pigment in light strokes for a vaporous effect. In Bacchus and Ariadne, the sky is not uniformly blue: it is a mosaic of touches that, from a distance, blend into a vibrant hue.
But perhaps the greatest trick came from Vermeer. In Girl with a Pearl Earring, the blue turban is painted with such economy that restorers initially thought it a mistake. In truth, Vermeer used a single layer of pure ultramarine, applied in one stroke, without retouching. A brushstroke so precise it seemed to defy the laws of optics.
These techniques were not mere shortcuts. They revealed a deeper truth: art, even in the Renaissance, was a matter of compromise. Between the desire for beauty and material constraints, between devotion and budget. Ultramarine, in this game, was both a tool and a symbol—of unattainable luxury, but also of a quest for perfection.
The scandal of stolen blues
The history of ultramarine is also one of fraud, counterfeiting, and even crime.
In 1508, Albrecht Dürer was swindled. A Venetian merchant sold him "first-quality ultramarine," which he used to paint The Feast of the Rosary. The problem? The blue turned gray within years. Dürer, furious, discovered he had been duped with a mixture of smalt and chalk. He wrote in his journal: "The merchant sold me mud, claiming it was sky."
Worse still: theft. In 1570, the painter Paolo Veronese was accused of diverting ultramarine meant for the decoration of the Doge’s Palace. Records from the time mention "a suspicious quantity of blue pigment" found in his workshop. Veronese got off with a fine, but the affair revealed a sordid reality: some artists did not hesitate to resell pigments stolen from their patrons.
The most famous case remains Michelangelo’s. In 1508, while painting the Sistine Chapel ceiling, Pope Julius II reproached him for wasting ultramarine. Michelangelo retorted sarcastically: "Your Holiness, I am painting the sky. Should I skimp on the color of God?" The pope, enraged, threatened to have him thrown from the scaffolding. The artist relented… in part. He did use ultramarine, but mixed it with azurite for the less visible areas.
These scandals showed one thing: ultramarine was not just a pigment. It was currency, a power struggle, an object of desire. And like anything of value, it attracted thieves, forgers, and artists willing to do anything to get their hands on it.
The fall and rebirth: when chemistry dethroned the mines
The golden age of natural ultramarine ended in 1826. That year, a French chemist, Jean-Baptiste Guimet, developed a method to synthesize the pigment. No more Afghan mines, caravans, or Venetian merchants. Ultramarine became accessible, cheap, mass-produced.
Artists embraced this revolution. The Impressionists, led by Monet, adopted synthetic blue for their skies and waters. Van Gogh used it in The Starry Night, where the celestial swirls seemed made of the same stuff as dreams. Even decorators got in on the act: in the nineteenth century, bourgeois salons were adorned with ultramarine draperies and wallpapers, as if to claim a little of the magic once reserved for gods and kings.
Yet something was lost in this democratization. Synthetic blue, however beautiful, lacked the mystical depth of the original. It missed the imperfections, the flecks of pyrite that glittered like stars, the unique nuances of each stone. As the art critic John Ruskin noted: "Natural ultramarine is alive. The synthetic is only a ghost of color."
Today, the mines of Sar-e-Sang are still active, but their production is marginal. Natural ultramarine remains used by a few artists and restorers, who pay fortunes for a few grams of this legendary blue. As for the Venetian workshops, they have vanished, taking with them the secrets of a thousand-year-old alchemy.
The invisible legacy: what blue has taught us
The story of ultramarine does not end with painting. It speaks of trade, power, faith, and even ecology. For this pigment, born in the Afghan mountains, traversed the centuries like an Ariadne’s thread linking civilizations.
It reminds us that art was never a matter of pure inspiration. Behind every masterpiece lie contracts, debts, compromises. That beauty has a cost—sometimes exorbitant. And that colors, far more than mere hues, are full-fledged actors in history.
Today, when you gaze upon the Virgin’s mantle in a cathedral or the sky in a Vermeer painting, remember: this blue did not come about by chance. It is the fruit of thousands of years of quest, suffering, and genius. A stone turned to color, turned to legend.
And if you listen closely, perhaps you will still hear, in the silence of museums, the echo of the miners of Badakhshan, the Venetian merchants, and the artists who made this blue far more than a pigment.
A promise of sky.
The blue worth its weight in gold: The secret epic of ultramarine | Art History
