Hydroniumpharmacosiderite

(H3O)Fe3+4(AsO4)3(OH)4 · 4H2O
IMA status
  • Approved
IMA symbol
Hpsd
IMA approved
2010
Also known as
  • Hydroniumpharmacosideriet
  • IMA2010-014

Where it forms, where it's found

Type locality
Cornwall
  1. England
  2. UK
6recorded occurrences
Source · OpenStreetMap

Safety & handling

Physical

Hardness
123456789102 – 3/ 10 MOHS
  1. 1Talc
  2. 2Gypsum
  3. 3Calcite
  4. 4Fluorite
  5. 5Apatite
  6. 6Orthoclase
  7. 7Quartz
  8. 8Topaz
  9. 9Corundum
  10. 10Diamond
Transparency
Transparent
Colour
Yellowish green
Streak
Light green
Tenacity
brittle
Cleavage

On (001)

Fracture
Irregular/Uneven
Density
2.559 g/cm³

Optical

Optical type
Isotropic
Birefringence
Anomalous birefringence with nmin = 1.690(2) and nmax = 1.692(2)
UV response
Not fluorescent
Isotropy testPPL ↔ XPL diagnostic
PPL intrinsic colour; no change on stage rotation
XPL extinct at every orientation

Crystallography

Crystal system
Isometric
Space group
P-4 3m
Cell parameters
a = 7.9587(2) Å
Type-locality form

A single yellowish green, slightly elongated cube, 0.17 mm in size.

Crystal structure

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
8OOxygenOxygen2115.999335.979
42.04%
33AsArsenicArsenic374.922224.766
28.12%
26FeIronIron455.845223.380
27.95%
1HHydrogenHydrogen151.00815.120
1.89%
Total799.245100.00%

Mass share = atoms × atomic mass ÷ molar mass × 100

From IMA formula

Synonyms

  • Hydroniumpharmacosideriet
  • IMA2010-014

In other languages

German
Hydroniumpharmakosiderit · IMA 2010-014
Italian
hydroniumpharmacosiderite

Classification

Strunz
10th ed.

8.DK.10

  • 8Phosphates, Arsenates, VanadatesClass
  • 8.DPhosphates, etc. with additional anions, with H2ODivision
  • 8.DKWith large and medium-sized cations, (OH, etc.):RO4 > 1:1 and < 2:1Group
  • 8.DK.10HydroniumpharmacosideriteSpecies
Dana
8th ed.

42.08.1a.04

  • 42Hydrated Phosphates, Etc.containing Hydroxyl or HalogenClass
  • 42.08(AB)5(XO4)3Zq·xH2OType
  • 42.08.1a— unnamed intermediate level —Group
  • 42.08.1a.04HydroniumpharmacosideriteSpecies

Group, growth & confusion

Literature, links & citation

Citations
  1. 2010Mills, S. J., Hager, S. L., Leverett, P., Williams, P. A., Raudsepp, M. (2010) The structure of H3O+-exchanged pharmacosiderite. Mineralogical Magazine, 74 (3) 487-492 doi:10.1180/minmag.2010.074.3.487DOI: 10.1180/minmag.2010.074.3.487
  2. 2010Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2010) New minerals and nomenclature modifications approved in 2010. CNMNC Newsletter No 3. Mineralogical Magazine, 74 (3) 577-579 doi:10.1180/s0026461x00054979 DOI: 10.1180/s0026461x00054979
  3. 2010Mills, S. J., Kampf, A. R., Williams, P. A., Leverett, P., Poirier, G., Raudsepp, M., Francis, C. A. (2010) Hydroniumpharmacosiderite, a new member of the pharmacosiderite supergroup from Cornwall, UK: structure and description. Mineralogical Magazine, 74 (5) 863-869 doi:10.1180/minmag.2010.074.5.863 DOI: 10.1180/minmag.2010.074.5.863
  4. 2015(2015) Hydroniumpharmacosiderite. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Hydroniumpharmacosiderite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/hydroniumpharmacosiderite-40152},
  note      = {Accessed 2026-05-11}
}