Vivianite

 ( Iron Minerals ) 

Vivianite () is a hydrated iron(II) phosphate mineral found in a number of geological environments. Small amounts of manganese Mn²⁺, magnesium Mg²⁺, and calcium Ca²⁺ may substitute for iron Fe²⁺ in its structure.Gaines et al (1997) Dana's New Mineralogy Eighth Edition. Wiley Pure vivianite is colorless, but the mineral oxidizes very easily, changing the color, and it is usually found as deep blue to deep bluish green prismatic to flattened crystals. Vivianite crystals are often found inside fossil shells, such as those of and , or attached to fossil bone. Vivianite can also appear on the iron coffins or on the corpses of humans as a result of a chemical reaction of the decomposing body with the iron enclosure.

It was named by Abraham Gottlob Werner, the "father of German geology", in 1817, the year of his death, after either John Henry Vivian (1785–1855), a Welsh-Cornish politician, mine owner and mineralogist living in Truro, Cornwall, England, or after Jeffrey G. Vivian, an English mineralogist.Although mindat.org claims "J. G. Vivian" is a typo for "J. H. Vivian", there is at least one reference that gives a full first name. The original description of Vivianite in Abraham Gottlob Werner, Letztes Mineral-System, Freiberg/Wien, 1817, reads „Der Name ist vom Hrn. B. R. Werner zu Ehren des Hrn. J. Vivian aus Truro in Cornwall, dem Er die Kentnis des Fossils verdankt, gebildet.“ “The It is ambiguous (and puzzling in its reference to B. R. Werner). As for Jeffrey G. Vivian, no other trace of him can be found in Google Books. Vivianite was discovered at Wheal Kind, in St Agnes, Cornwall.

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Vivianite group Vivianite group minerals have the general formula A₃(XO₄)₂·8H₂O, where A is a divalent metal cation and X is either phosphorus or arsenic, and they are monoclinic.Journal of the Russell Society (2006) 9:3

Group members are:

Monoclinic

Monoclinic

Monoclinic

Monoclinic

Monoclinic

Monoclinic

Monoclinic

Monoclinic

Monoclinic

Monoclinic

Related:

– Bobierrite: Mg₃(PO₄)₂·8H₂O

– Symplesite: Fe²⁺₃(AsO₄)₂·8H₂O

– Metaköttigite: Zn₃(AsO₄)₂·8H₂O

– Metavivianite: (Fe²⁺,Fe³⁺)(PO₄)₂(OH)·H₂O.

Note: Metavivianite, that vivianite readily alters to, is not a member of the vivianite group because it contains trivalent Fe³⁺ cations.

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Structure In pure end member vivianite all the iron is divalent, Fe²⁺, but there are two distinct sites in the structure that these ions can occupy. In the first site, the Fe²⁺ is surrounded by four water molecules and two , making an octahedral group. In the second site, the Fe²⁺ is surrounded by two water molecules and four oxygens, again making an octahedral group. The oxygens are part of the phosphate groups (PO₄³⁻), that are tetrahedral. The vivianite structure has chains of these octahedra and tetrahedra that form sheets perpendicular to the a-crystal axis. The sheets are held together by weak bonds, and that accounts for the perfect cleavage between them.

The crystals are monoclinic, class 2/m, space group C 2/m, with two formula units per unit cell (Z = 2). The approximate values of the unit cell parameters are:

a = 10.1 Angstrom, b = 13.4 Å, c = 4.7 Å and β = 104.3°,

with slightly different values given by different sources:

a = 10.086 Å, b = 13.441 Å, c = 4.703 Å, β = 104.27°

a = 10.06 Å, b = 13.41 Å, c = 4.696 Å, β = 104.3°

a = 10.034–10.086 Å, b= 13.434–13.441 Å, c= 4.687–4.714 Å, β = 102.65–104.27°

a = 10.024(6) Å, b = 13.436(3) Å, c = 4.693(4) Å, β = 102.30(5)°

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Appearance

The mineral may occur as crystals, or as masses or concretions. The crystals are usually prismatic parallel to the c-crystal axis, and flattened perpendicular to the b-axis. Crystal habit crystals are rarer. They may also occur as Crystal habit (star-shaped) groups, or encrustations with a Crystal habit or Crystal habit structure. Unaltered specimens are colorless to very pale green, but they Redox on exposure to light (and possibly also in situ) to blue, then darker green, brown, purple and purplish black. The streak is white, altering to dark blue or brown. Crystals are transparent to translucent with a vitreous luster, pearly on the cleavage surface, or dull and earthy.

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Optical properties

Vivianite is biaxial (+) with refractive indices approximately:

n_α = 1.58, n_β = 1.6, n_γ = 1.6, but different sources give somewhat different values

n_α = 1.579, n_β = 1.602, n_γ = 1.637

n_α = 1.579–1.616, n_β = 1.602–1.656, n_γ = 1.629–1.675

n_α = 1.58–1.626, n_β = 1.598–1.662, n_γ = 1.627–1.699

Birefringence: δ = 0.050–0.059 or 0.0470–0.0730

The refractive indices increase with increasing oxidation, the birefringence decreases, and the pleochroism on {010} becomes stronger.

The angle between the optic axes, 2V, has been measured as between 63° and 83.5°; it can also be calculated from the refractive indices, giving a value between 78° and 88°. The dispersion of the optic axes is weak, with r or non-existent. Vivianite is pleochroic with X= blue, deep blue or indigo-blue; Y= pale yellowish green, pale bluish green or yellow-green; Z= pale yellowish green or olive-yellow. X is parallel to the b-crystal axis and Z is inclined to the c-crystal axis at an angle of 28.5°. It is not fluorescent.

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Physical properties

Vivianite is a soft mineral, with Mohs hardness only to 2, and specific gravity 2.7. It splits easily, with perfect cleavage perpendicular to the b-crystal axis, due to the sheet-like structure of the mineral. It is sectile, with a fibrous fracture, and thin laminae parallel to the cleavage plane are flexible. It is easily soluble in acids. It has a melting point of , it darkens in color in H₂O₂, and is not radioactive.

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Geological setting

Vivianite is a secondary mineral found in a number of geologic environments: the oxidation zone of metal ore deposits, in granite pegmatites containing phosphate minerals, in and Glauconite, and in recent alluvial deposits replacing organic material such as peat, lignite, bog iron ores and forest soils (all). Bones and teeth buried in Bog are sometimes replaced by vivianite. Some authors say that it is particularly associated with gossan, but this is disputed by Petrov.

Associated minerals include metavivianite, ludlamite, pyrite, siderite and pyrrhotite. Hydrothermal veins produce the best crystal specimens with the classic gemmy green color.

The type locality is Wheal Kind (Wheal Kine), West Wheal Kitty group, St Agnes, St Agnes District, Cornwall, England.

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Photo-oxidation

Oxidation of vivianite is an internal process; no oxygen or water enters or leaves the mineral from the outside. A visible light photon knocks a proton out of a water molecule, leaving a hydroxide ion (OH⁻). In turn, a divalent iron Fe²⁺ loses an electron to become Fe³⁺, i.e., it is oxidized and balances the charge. This process starts when visible light falls on the vivianite, and it can occur within a few minutes, drastically changing the color of the mineral. Eventually, the vivianite changes to a new species, metavivianite Fe²⁺₂Fe³⁺(PO₄)₂(OH)·7H₂O, which usually occurs as paramorphs after vivianite. Alfredo Petrov, 2006 on Mindat

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Pigment

As pigment, vivianite is known as "blue ochre" and has been used since Roman times, though its use in oil painting was somewhat limited. Vivianite at ColourLex It saw some use in wall paintings and Polychrome of medieval Germany and England, as well as Baroque and Rococo Austria and Germany. Noble, Petria & van Loon, Annelies. (2005). New insights into Rembrandt's Susanna, changes of format, smalt discolouration, identification of vivianite, fading of yellow and red lakes, lead white paint. Art Matters-Netherlands Technical Studies in Art. 2. 76-96. 10.64655/AM.2.tas1963. Most notably, spectroscopic analysis has determined its use in the Baroque art of the Dutch Golden Age, particularly the work of Aelbert Cuyp.Stege, It has been found in Johannes Vermeer The Procuress in the blue-grey parts of the carpet in the foreground,H. Stege, C. Tilenschi und A. Unger. Bekanntes und Unbekanntes – neue Untersuchungen zur Palette Vermeers auf dem Gemälde „Bei der Kupplerin“. In: Uta Neidhardt und Marlies Giebe (Ed.), Johannes Vermeer – Bei der Kupplerin, Ausstellungskatalog Dresden 2004, pp. 76–82., and is prominent in the foliage of Rembrandt Susanna (1636), an early predecessor to his Susanna and the Elders. Vivianite paints pose some problems to art conservators due to its susceptibility to blanching, which produces a hazy look to the work, and further oxidation producing the yellow-brown metavivianite, which can alter the hue and temperature of the composition considerably.

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Localities

• Brazil. Cigana Mine, Galileia, Minas Gerais, with muscovite and pyrite.The Mineralogical Record (2004) 35-2:156 Typically wedge-shaped crystals of vivianite to 11 cm across, of medium lustre, smoke-blue color and good transparency on matrix of sharp silvery muscovite plates, some with druses of pyrite microcrystals.The Mineralogical Record (2004) 35-3:252
• Bolivia: Llallagua, Potosi: Crystals to 10 cm at the Siglio XX mine. Transparent bottle-green crystals to 10 cm from the San Jose/San Firmin vein. In general, the vivianite occurs as prismatic crystals on a matrix of botryoidal goethite derived from the alteration of pyrite and marcasite. Specimens found in 2000 were associated with childrenite, cronstedtite, pyrrhotite, franckeite and pink massive sphalerite.The Mineralogical Record (2006) 37-2:156
• Cameroon: The world's largest vivianite crystals (more than a meter long) from mud.
• Canada: In bog iron at Côte St Charles, Vaudreuil-Soulanges, Montérégie, Québec.
• Germany: In the limonite ores in Amberg-Auerbach and in the pegmatites of Waidhaus, Bavaria.
• Japan: At Nagasawa, Iwama-machi, Ibaraki Prefecture, vivianite was found along fractures in rocks rich in graphite, pyrite and pyrrhotite. The vivianite is intimately associated with pyrite and occurs as very thin tabular crystals, up to 10 cm in length.
• Kosovo. Trepča Mines, Stari Trg. Thick prismatic crystals up to 10 cm long and 2 cm thick, relatively stable. Deep green in color and transparent, commonly resting on pyrrhotite or pyrite, and in some cases on quartz or carbonates.The Mineralogical Record (2007) 38-4:290
• Mexico: In blue-green gem quality crystals to 8 cm at the San Antonio Mine, Santa Eulalia, Chihuahua.
• Russia: In sedimentary stratified iron ore deposits on the Taman peninsula on the Black Sea.
  (2025). 9780962209734, Mineral Data Publ. ISBN 9780962209734
• Slovenia: In Idrija mine, 2 mm bluish vivianite crystals in fissures of Langobardian sandstone were found.
  (2025). 9783642316319, Springer Berlin / Heidelberg. ISBN 9783642316319
• Spain: At the Brunita mine, Cartagena, Murcia, vivianite was found as deep green crystals, up to 8 cm
  Miguel Calvo (2025). 9788495063960, Escuela Técnica Superior de Ingenieros de Minas de Madrid. Fundación Gómez Pardo. Madrid, Spain. ISBN 9788495063960
• Ukraine: In the Kerch iron ore basin in the Crimean Peninsula, peatlands of Volyn' region
  (2025). 9786177565146, НТУ «ХПІ». ISBN 9786177565146
  and Zakarpattia region.
• US: In diatomite in a Tertiary period lake bed near Burey, Shasta County, California.
• US: In green sand at Middletown, New Castle County, Delaware.
• US: Blackbird Mine, Lemhi County, Idaho. Crystals in shades of pink, green, greyish blue, purple and purplish black, as well as colorless. The unique deep purple color of some Blackbird mine specimens is characteristic of the locality. Some single crystals have both purple and green zones. Vivianite crystals from the Blackbird Mine are usually elongated and blade-like. They occur as singles and groups on dark altered schist and on white quartz. Associated minerals include ludlamite, quartz and siderite.The Mineralogical Record (2010) 41-4:366
• US: Abundant in the pegmatites of Newry, Maine.
• New Zealand: Small amounts of vivianite are present within the sediments of Lake Kohangapiripiri.Cochran, U., Goff, J., Hannah, M., and Hull, A. (1999) Relative stability on a tectonically active coast: paleoenvironment during the last 7000 years at Lake Kohangapiripiri, Wellington, New Zealand, Quaternary International, 56, 53–63

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On Mars

A September 10, 2025 paper published in Nature reported the "likely" detection of vivianite and greigite in the Jezero crater on Mars, by the Perseverance rover. It is considered a potential biosignature of iron-oxidizing biota.

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See also

• List of minerals
• List of minerals named after people

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External links

• Vivianite as a pigment at ColourLex

Categories: Iron Minerals, Phosphate Minerals, Monoclinic Minerals, Minerals In Space Group 10, Vivianite Group, Minerals Described In 1817

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