Ferrous phosphate

From CAMEO
Jump to: navigation, search
Vivianite

Description

A hygroscopic, blue-gray powder that occurs naturally as the mineral vivianite. Vivianite was described after discovery in the St. Agnes mine in Cornwall in 1817. It has been called 'blue ocher' and has been found in Roman paint residues. Ferrous phosphate is used as a colorant in ceramics.

Synonyms and Related Terms

iron phosphate; vivianite; blue ochre; blue ocher; ocre de fer (Fr.)

Raman

VivianiteRS.jpg


Other Properties

Soluble in mineral acids. Insoluble in water.

Euhedral crystals with strong pleochroism from colorless to lilac blue. Strongly birefringent under crossed polars.

Composition Fe3(PO4)2.8H2O
CAS 14940-41-1
Density 2.58-2.68
Molecular Weight mol. wt. = 357.48
Refractive Index 1.60; 1.63; 1.65

Hazards and Safety

Slowly decomposes and darkens in light and air.

Comparisons

Characteristics of Common Blue Pigments


Sources Checked for Data in Record

  • Nicholas Eastaugh, Valentine Walsh, Tracey Chaplin, Ruth Siddall, Pigment Compendium, Elsevier Butterworth-Heinemann, Oxford, 2004
  • Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993
  • R.D. Harley, Artists' Pigments c. 1600-1835, Butterworth Scientific, London, 1982
  • The Merck Index, Martha Windholz (ed.), Merck Research Labs, Rahway NJ, 10th edition, 1983 Comment: entry 4101