What the Body Becomes
Vivianite forms in graves, colors masterworks, and cannot stay blue. It is also in the drawer.
In the summer of 2023, a colleague introduced me by email to an artist named Melonie Ancheta. The introduction was two sentences. Melonie had been researching a particular mineral for twenty-five years. She thought we should talk.
I wrote back the same day.
Melonie is a Northwest Coast Native pigment specialist — her work centers on the traditional paints of the Haida and Tlingit peoples, what those paints were actually made of, and what happens to them over time on the objects they were applied to centuries ago. The mineral connecting us was vivianite. She was trying to stop it from changing color on Tlingit ceremonial objects held in museum collections across North America. I was trying to stop it from changing color in our gem and mineral hall. We had arrived at the same problem from completely different directions, separated by geology on one side and art history on the other, and neither of us had solved it.
Nobody has.
That’s what happens with vivianite. Everyone who gets close to it eventually ends up with the same unanswered question. And the more you understand about what this mineral actually is — where it comes from, how it forms, what it’s made of — the less the unanswered question feels like a failure, and the more it starts to feel like the point.
The Specimen in the Dark
We have a vivianite specimen at NHMLAC that I cannot put on display.
Vivianite is an iron phosphate mineral — one of the most visually arresting in any collection, and almost entirely unknown outside mineralogy. When you encounter it, the blue stops you.
If you’ve seen the Instagram post, you know what it looks like: a stack of dark metallic plates peeling apart from each other, with flashes of deep blue-green caught in the cracks between them, like someone has been forcing a book open from the spine and light got in between the pages. The outer surfaces are nearly black. The interior surfaces — the ones only recently exposed — are the color of a deep ocean in a painting you can’t quite believe is real.
The specimen has been doing this for decades, probably longer. It was doing it before I became curator. It will keep doing it after I’m gone. We keep it in the dark because light accelerates the process, and in the dark the process merely continues rather than races. The museum holds things in perpetuity — that is the entire institutional commitment — and so we hold this one in a drawer, and visit it occasionally, and note that it has progressed.
What is it doing? It is, in the most literal chemical sense, becoming something else.
Fe²⁺ and the Eight Waters
Vivianite’s formula is Fe₃(PO₄)₂·8H₂O. Iron, phosphate, and eight water molecules held together in a structure so water-rich it feels almost biological — which turns out to be entirely appropriate.
In a fresh crystal, all three iron atoms are in their reduced state: Fe²⁺, ferrous iron. This is iron that has held onto its electrons. It is the same oxidation state as the iron in your hemoglobin right now, carrying oxygen through your blood. In this state, the crystal is completely colorless. Not pale. Not faintly blue. Colorless — transparent as glass, with no color to speak of.
Then light arrives.
A visible photon strikes the crystal and knocks a proton loose from one of those eight water molecules. The displaced charge has to go somewhere, so a nearby Fe²⁺ gives up an electron and becomes Fe³⁺ — oxidized iron, iron that has lost something. Now two iron atoms sit side by side in the same lattice: one with the electron, one without. And the electron begins to move.
It hops. Back and forth, Fe²⁺ to Fe³⁺, Fe³⁺ to Fe²⁺, driven by the energy of incoming light. Physicists call this intervalence charge transfer, but what it looks like from the outside is blue — because the hopping absorbs the orange and red end of the spectrum and reflects what remains. The blue you see in vivianite is not a stable property of the mineral. It is the color of instability itself. It is what electron theft looks like, made visible.
And it cannot hold. The oxidation continues. More Fe²⁺ becomes Fe³⁺. The mixed-valence sweet spot that produces blue gradually disappears — there is less and less Fe²⁺ left to complete the pair, less hopping, less blue. The color deepens toward dark green, then black, then — when the iron is fully oxidized, every electron surrendered — it flips entirely. Fully oxidized iron phosphate absorbs blue and reflects yellow-brown. The end product is likely santabarbaraite: Fe³⁺₃(PO₄)₂(OH)₃·5H₂O. Same phosphate backbone, same basic architecture, every electron gone.
The full sequence: colorless, then blue, then dark, then yellow-brown. The same atoms the entire time, the same crystal shape, just electrons redistributed — a completely different mineral at each stage, wearing the same external form. The blue was never the destination. It was always the middle.
Somewhere in that middle, the formula is Fe²⁺Fe³⁺₂(PO₄)₂(OH)₂·6H₂O: metavivianite. A ghost of the original structure.
The specimen in our drawer is somewhere in this sequence. The black outer surfaces are late-stage. The blue-green caught in the cracks is mid-stage, exposed recently enough that the hopping still has somewhere to go. The crystal is not one thing — it is a gradient, a reaction front moving inward from every surface that has ever seen light. In the most honest description available to mineralogy, it is a record of every photon that has reached it.
This is why I cannot put it on display. The lights would finish what has already started.
The body does not stop being geochemistry when it stops being alive.
What Makes It, and Where
To understand why vivianite keeps appearing everywhere — in geological specimens, in burial sites, in the mud under peat bogs, in the sediment of alpine lakes — you need to understand what it requires. Three things: iron, phosphate, and very little oxygen. Reducing conditions, in the chemical vocabulary. That combination sounds specific. It isn’t.
Peat bogs. Lake sediments. Waterlogged soils. The reducing mud at the bottom of a marsh. The interior of a decomposing organism. All of these qualify. The organic matter provides phosphate as it dissolves. If iron is nearby — in the surrounding sediment, in buried metal objects, in the rocks of a glacier — the two meet in solution and nucleate. Crystals begin to grow. Colorless at first. Then the light finds them.
The places vivianite forms most readily are also, not coincidentally, places humans have been depositing their dead for thousands of years.
In 1996, a torso was recovered from a bay of Lake Brienz in Switzerland, exposed by an underwater landslide triggered by an earthquake. The body — nicknamed Brienzi by the forensic team, in the tradition of Ötzi — had been in the water since approximately the 1770s. Parts of it were blue. Vivianite had grown on the preserved adipose tissue, fed by iron from the lake sediment and phosphate from the dissolving bone. The forensic investigators used the mineral’s presence to reconstruct the burial environment and estimate the time since death. The vivianite had been keeping records the entire time, in the dark, at the bottom of the lake, waiting for an earthquake to bring it into the light.
Ötzi the Iceman — 5,300 years old, recovered from the Ötztaler Alps — carries blue spots on his skin where he was in contact with iron-bearing rocks. The glacier provided the iron. His own body provided the phosphate. The chemistry did not require anyone’s intent or awareness.
And US airmen missing in action in Vietnam, recovered decades after a 1963 crash, were found with blue encrustations on their skeletal remains. The iron came from the corroding aircraft. The vivianite told investigators the men had been buried in waterlogged soil — information recoverable no other way. A mineral that forms in the space between iron and phosphate and darkness had written a forensic record that outlasted every other witness.
Then there is John White, a railway engineer who died in 1861 and was buried in a cast iron coffin fitted with a small glass window — a Victorian custom, so mourners could see the face of the deceased when the lid was closed. At some point after burial the glass broke. Groundwater seeped in, met the iron of the coffin and the phosphate of the dissolving body, and over the following century assembled itself into vivianite crystals. When the coffin was exhumed during an archaeological rescue excavation more than a hundred years later, it was full of blue. John White had become, in part, a mineral. Nobody planned it. The chemistry simply proceeded.
Vivianite is not a rare mineral. It forms wherever the conditions align. And the conditions align, with remarkable frequency, wherever something organic has ended in the presence of iron and water.
What Your Body Is
Your body contains approximately 4–5 grams of iron. Most of it is in hemoglobin — the protein in red blood cells that carries oxygen — where the iron sits at the center of a ring-shaped molecule in its ferrous, Fe²⁺ form. Reduced iron. The same oxidation state as colorless, fresh vivianite.
Your body also contains roughly 700 grams of phosphorus, most of it locked into the mineral structure of your bones and teeth as hydroxyapatite: Ca₁₀(PO₄)₆(OH)₂. The phosphate groups in that formula are the same phosphate groups in vivianite’s formula. Right now they are doing a different job. They are making your skeleton rigid.
When decomposition begins, hemoglobin breaks down and releases its iron into the surrounding environment. Bone apatite dissolves and releases its phosphate. In a waterlogged, reducing burial environment — low oxygen, iron present — those two populations meet in solution for the first time. And they precipitate.
You are carrying the precursor minerals right now. The only thing preventing their reorganization into blue-green crystals is you.
The Painters and the Bog
In the 12th century, a painter decorating the Holy Sepulchre Chapel at Winchester Cathedral reached for blue. Not lapis lazuli — too expensive, too rare, too far from Hampshire. Instead, vivianite: the earthy blue-green mineral found in the peat and alluvial deposits of the local countryside, at Fordingbridge and the Isle of Wight, within traveling distance of the cathedral. The Getty Conservation Institute’s technical analysis of the chapel paintings established that the vair lining of Nicodemus’s cloak — the heraldic pattern of alternating pale blue and white squirrel fur — was rendered in vivianite. The conservators noted it was chosen not as an economical substitute but for its distinctive deep indigo quality, set against natural ultramarine for contrast. It was a deliberate aesthetic decision about a specific color.
They were not painting with a stable color. They were painting with a process.
The paintings at Winchester look green now. Nobody painted them green. Some of the vivianite particles have oxidized all the way through the blue-black stage and kept going — past metavivianite, into the fully oxidized iron phosphate territory where the color flips to yellow-brown. The yellow particles and the remaining blue particles, mixed together at the pigment grain scale, average out to green. The Winchester green is not a color anyone chose. It is the arithmetic of eight centuries of oxidation, caught partway through, different grains at different stages of the same sequence. The original intent is now recoverable only through laboratory analysis.
Four centuries later, in Dordrecht, Aelbert Cuyp was painting the Dutch countryside in warm golden light. The peat bogs around Dordrecht — the flat, waterlogged geography Cuyp knew as home — are exactly the kind of iron-phosphate-rich, anaerobic environment where vivianite forms as amorphous blue-green clay, easy to collect, easy to grind. Conservation scientists examining Cuyp’s paintings have identified vivianite in multiple works: in a milkmaid’s skirt in The Large Dort, in atmospheric green passages, in the cool distance of his landscapes. That blue-grey wash in a Cuyp painting is, in part, bog iron phosphate — the same chemistry, from the same kind of waterlogged organic ground, that produces vivianite in decomposing matter. Cuyp was painting the landscape partly with itself.
He was not the only one. Vivianite has been identified in works from the workshops of Rembrandt and Vermeer. It turns up in the grey-blue of a carpet in Vermeer’s The Procuress. The broader pattern concentrates heavily in 17th-century Dutch painting, almost certainly because the Dutch peat bog was local, free, and abundant. The great masters of Northern European light were painting partly in the chemistry of decomposition.
And the paintings have been changing ever since. The vivianite in The Large Dort has degraded. The blue in the milkmaid’s skirt is no longer quite what Cuyp applied. Same reaction, same direction, same inexorable sequence — just on a longer timescale than the specimen in our drawer, slowed but not stopped by climate-controlled gallery conditions. The Large Dort is mid-transformation, hanging in the National Gallery.
This is the thing about vivianite as a pigment: the painters who used it were, knowingly or not, applying a material that was going to keep reacting. The blue was transitional when they brushed it on. They were not painting with a stable color. They were painting with a process.
The People Who Already Knew
Melonie Ancheta’s 2019 paper in the American Indian Culture and Research Journal established something that two hundred years of Northwest Coast scholarship had gotten wrong. The blue paint on Haida and Tlingit ceremonial objects — masks, war helmets, shaman’s regalia, bentwood chests — was not, as had been consistently assumed and repeated without a single laboratory test, a copper oxide. It was vivianite. Iron phosphate. The mineral that forms in bones and decomposing organic matter, pulled from peat bog deposits along the coast.
The error correction came from SEM/EDX analysis. The scholarly literature had simply repeated the first wrong guess for two hundred years. The objects themselves knew the truth the entire time. Nobody thought to ask them until Melonie did.
What makes the identification remarkable is not just the correction. It is what the identification means. The Haida and Tlingit did not use vivianite merely because it was the available blue. Other blues became available over time — azurite, Prussian blue in the early 1700s, then cobalt and cerulean — and artists like Charles Edenshaw were still choosing vivianite into the 1900s for specific categories of objects. The new pigments did not replace it for those uses. They could not.
The reason is that vivianite was not functioning primarily as a color. It was functioning as a material with properties no synthetic blue could replicate. Among the Haida, blue was a liminal color — a portal color, associated with the border between the living world and the spirit world. In a survey of three hundred masks, Ancheta found blue paint in tertiary fields 75% more often on shamanic objects than on non-shamanic ones. Shamans painted their regalia with it to move between realms. Warriors painted their helmets blue so their faces resembled the dead. And the mineral chosen to make that blue was specifically the one that forms in bones — the one that grows in the space between the living system and the mineral system, the one that is always in the middle of becoming something else.
The chromism was not a problem to be solved. It was part of the material’s power. A paint that transforms — that starts one color and becomes another over time — corresponded directly to a cosmology in which transformation was fundamental. The Haida believed bones were the essence of life, symbols of death and regeneration. A mineral that forms in bone, that changes color when light reaches it, that moves between states and cannot be fixed in place: this was not a pigment with an unfortunate instability. This was exactly the right material for objects used at the border of life and death.
It is also worth remembering that none of these objects were made for electric light. They were made for firelight. In shifting flames and moving shadow, the matte blue surface of vivianite paint — absorbing light rather than reflecting it, unlike every other pigment in the palette — would have animated differently from the black and red around it. The chromism was not a static property to be preserved. It was a behavior, visible in the right conditions, in the right context, to people who understood what they were looking at.
The Haida and Tlingit understood something that academic mineralogy spent two centuries not examining: where a material comes from is part of what it is. Vivianite formed in bone carries the meaning of bone. That is not metaphor. It is a material epistemology, and it is more rigorous than the scholarship that ignored it for two hundred years.
Chromism in Three Institutions
Winchester. Dordrecht. Los Angeles.
The bentwood chests attributed to Albert Edward Edenshaw at the University of British Columbia’s Museum of Anthropology are displayed in a glass room with constant UV exposure. The vivianite in their tertiary fields — once a deep, matte, velvety blue applied with water, no binder — has darkened toward black. The blue is nearly gone from entire panels. The object is still in the collection. The color it was made with is finishing its transformation under gallery lighting.
In the National Gallery in London, The Large Dort hangs with its milkmaid’s skirt altered — the vivianite Cuyp applied in the mid-17th century has degraded, shifted away from what he mixed. The conservators who cleaned and restored it documented the change. They could not reverse it.
In storage in Los Angeles, a geological crystal — not a pigment, not a painting, just a specimen from the earth — is doing the same thing. Pages peeling. Black where the light reached. Blue-green in the fresh cracks. The same Fe²⁺ oxidizing to Fe³⁺, the same water molecules being lost, the same slow drift from vivianite toward metavivianite, one photon at a time.
The mineral does not distinguish between a 12th-century English cathedral wall, a 17th-century Dutch canvas, a 19th-century Haida ceremonial chest, and a geological specimen drawer in a natural history museum. It is running the same reaction in all of them. Melonie cannot stop it on the Edenshaw chests. The National Gallery cannot stop it in the Cuyp. I cannot stop it in the drawer. We can slow it — keep things in the dark, control the temperature, filter the UV — but we cannot stop it, because the chemistry does not require our participation to proceed.
Melonie once described vivianite as a diva material — unpredictable, with behaviors nobody fully understands. She has been studying it for twenty-five years and still cannot fully predict when or why it darkens on one object and not another. I have been trying to stabilize it under museum lighting conditions for most of my tenure. We found each other because we were both losing the same argument from opposite directions.
What stays with me is not that vivianite changes color. It is that the spectacular, irreproducible blue is not the beginning or the end but the middle. That is what the Haida painted on the faces of shamans at the border of life and death. That is what Cuyp brushed into the shadow of a milkmaid’s skirt on the river at Dordrecht. That is what the Winchester painter reached for when rendering the squirrel-fur lining of a cloak. That is what is in the drawer. Everyone, across all these contexts and centuries, has been trying to hold onto the middle of a transformation that was already underway before they found it.
The Close
The specimen in our drawer is not entirely vivianite anymore. It is somewhere between vivianite and metavivianite — the same external crystal form, a different internal mineral. The museum holds it because that is the commitment: perpetual care for the object, whatever state the object is currently in.
There is a third object in the drawer. A few years ago, Bob Hazen — mineralogist at the Carnegie Institution and one of the architects of mineral evolution theory, the framework that tracks how Earth’s mineral diversity expanded alongside biological complexity — donated a sample of vivianite-bearing clay to NHMLAC. It came from Maryland, collected from biomass and concrete deposits along a riverbank. Evidence of anthropogenic mineralization: vivianite forming right now, in the present, from modern organic waste along an industrial waterway. Same iron-phosphate-reducing chemistry, same three requirements — iron, phosphate, very little oxygen — but the organic matter is not ancient peat or a centuries-old burial. It is recent. It is us.
The clay is grey-blue, partially oxidized already — the same earthy, amorphous form that the Haida collected from coastal deposits and ground into pigment. Not the spectacular crystal. The working material. It sits in the drawer next to the splitting geological specimen, and together they show you the two faces of the same mineral: the dramatic and the humble, the ancient and the contemporary, the geological and the accidental.
The sequence does not end at metavivianite. Given enough time and light, the iron continues its work, the structure continues to shift, and eventually the blue is entirely gone — the mineral arrives at santabarbaraite, yellow-brown, fully oxidized, stable at last. The transformation completes. The Winchester paintings got there centuries ago. The specimen in the drawer is still en route.
You are upstream of all of this. Your hemoglobin iron and your apatite phosphate are precursors in a sequence that vivianite sits in the middle of. The mineral world is not waiting for you. It has been running this reaction for as long as there has been iron and phosphate and water on this planet. You are a temporary organization of materials that have cycled through this process before and will do so again.
The Haida painted it on the faces of shamans because they understood that the border between living and not-living is not a wall. It is a gradient, and vivianite is one of the places the gradient is visible. The reaction is happening now, downstream from a waste site in Maryland, in a painting in the National Gallery, in a ceremonial chest in Vancouver, in a drawer in Los Angeles. And in the iron in your blood, patient and reduced, waiting for conditions that will not arrive while you are still organizing them otherwise.
I am still trying to stop the specimen from changing color. Melonie is still trying to stop the paint on the Edenshaw chests from going dark. Neither of us is going to fully succeed, and the mineral, in its patient way, is not particularly concerned.
It has been in the middle of becoming something else for longer than there have been people to notice.
References
Ancheta, Melonie. “Revealing Blue on the Northern Northwest Coast.” American Indian Culture and Research Journal43:1 (2019). Available at nativepaintrevealed.com.
Howard, Helen. "Pigments of English Medieval Wall Painting." In Historical Painting Techniques, Materials, and Studio Practice, edited by Arie Wallert, Erma Hermens, and Marja Peek. Getty Conservation Institute, 1995. Available open access at: https://www.getty.edu/conservation/publications_resources/pdf_publications/pdf/historical_paintings.pdf
Spring, Marika. “Pigments and Colour Change in the Paintings of Aelbert Cuyp.” In Aelbert Cuyp, exhibition catalog, National Gallery of Art, Washington, October 7, 2001–January 13, 2002. Edited by Arthur K. Wheelock Jr. Amsterdam/London, 2001–2002, pp. 65–73.
Spring, Marika, and Larry Keith. “Aelbert Cuyp’s ‘Large Dort’: Colour Change and Conservation.” National Gallery Technical Bulletin (London: National Gallery, 2009). Available at nationalgallery.org.uk.
Fascinating. And beautifully written. Thank you.
Thank you for the touching introduction to vivianite. I find it fascinating that I am an ancestor to a mineral!