Vivianite


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vivianite

[′vi·vē·ə‚nīt]
(mineralogy)
Fe3(PO4)2·8H2O A colorless, blue, or green mineral in the unaltered state (darkens upon oxidation); crystallizes in the monoclinic system and occurs in earth form and as globular and encrusting fibrous masses. Also known as blue iron earth; blue ocher.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Vivianite

 

(named in 1817 after the English mineralogist J. G. Vivian), a mineral, a hydrous ferrous phosphate: Fe3(PO4)2’ 8H2O. It crystallizes in a monoclinic system and occurs in powdery or dense masses. Vivianite has a hardness of 1.5-2.0 on the mineralogical scale, a density of 2,680-2,710 kg/m3, and a pale green color that turns blue in air. Formed by exogenous processes, it is widespread in peat bogs and in sedimentary iron ore deposits that are rich in phosphorus. The mineral is used as a phosphorus fertilizer and in making dark blue paint.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Postma D (1980) Formation of siderite and vivianite and the pore-water composition of a recent bog sediment in Denmark.
Vivianite is a widespread mineral in lacustrine sediments (see samples of world occurrences in Fagel et al.
It is also possible that phosphate minerals did not form because not enough iron was available for precipitation of variscite, strengite, or vivianite. The Seabrook soils at the research site were located near the front of the drainfield trenches and between the OWS and the estuary.
However, with the passage of time, the remaining "cornflower blue" mineral inclusions also found in these units, which may be vivianite crystals, retained their coloration and, if anything, had only deepened in color.
For example, Ptacek (1998) describes the elevated presence of vivianite, an amorphous ferric phosphate, which has been formed following dissolution and subsequent precipitation in the more reduced lower zones of the aquifer.
Irish Stallion Farms EBF Cooley Fillies & Mares Stakes 8.00 Dundalk 1m, Listed ATR VVCARD, page 76 DUNDALK has long been a happy hunting ground for Michael Halford and he runs four - Petticoat, Surrounding, Terzetto and Vivianite - in today's mile feature.
This daughter of Bated Breath shaped with plenty of promise on her belated debut at the Curragh in late July, finishing third, beaten less than four lengths, behind Park Bloom and subsequent winner Vivianite.
We believe this is the first reported occurrence of vivianite in western Tennessee.
The standards selected for Fe were fayalite ([Fe.sub.2]Si[O.sub.4]), magnetite ([Fe.sub.3][O.sub.4]), goethite (FeOOH), siderite (FeC[O.sub.3]), vivianite ([Fe.sub.3](P[O.sub.4]).8[H.sub.2]O), hematite ([Fe.sub.2][O.sub.3]), green rust-Cl ([(Fe, [Mg.sup.2+]).sub.6] [([Fe.sup.3+]).sub.2][(OH).sub.18].4[([H.sub.2]O).sub.18]Cl), and green rust-S[O.sub.4] ([(Fe,[Mg.sup.2+]).sub.6] [([Fe.sup.3+]).sub.2][(OH).sub.18].4[([H.sub.2]O).sub.18]S[O.sub.4]).
Thin section and scanning electron microscope images reveal that these cleavages are defined by microveins of calcite, gypsum, and montmorillonitic clays with hematite and vivianite, and that there is some evidence for silica dissolution.