Hydroxylhedyphane

Ca2Pb3(AsO4)3(OH)
IMA status
  • Approved
IMA symbol
Hhdy
Discovered
1891
IMA approved
2018
Also known as
  • Hydroxylhedyphaan
  • IMA2018-052

Where it forms, where it's found

Geological setting

Långban Fe–Mn–(Ba–As–Pb–Sb) deposit

Type locality
Långban Mine
  1. Långban Ore District
  2. Filipstad
  3. Värmland County
  4. Sweden

59.8554°, 14.2648°

2recorded occurrences
Source · OpenStreetMap

Safety & handling

Physical

Colour
Colorless

Crystallography

Crystal system
Trigonal
Space group
#79
Cell parameters
a = 10.0414(3) Å · c = 7.2752(2) Å
Unit cell volume
635.28 ų
Z
2
Morphology

Prismatic crystals, up to 2.5 cm in length.

Type-locality form

Colourless prismatic crystals, up to 2.5 cm in length, forming an oriented intergrowth with a serpentine-subgroup mineral, fracture-fillings cutting braunite and hausmannite ore.

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
82PbLeadLead3207.200621.600
54.74%
33AsArsenicArsenic374.922224.766
19.79%
8OOxygenOxygen1315.999207.987
18.32%
20CaCalciumCalcium240.07880.156
7.06%
1HHydrogenHydrogen11.0081.008
0.09%
Total1135.517100.00%

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

From IMA formula

Synonyms

  • Hydroxylhedyphaan
  • IMA2018-052

In other languages

German
Hydroxylhedyphan · IMA 2018-052

Classification

Strunz
10th ed.

8.BN.05

  • 8Phosphates, Arsenates, VanadatesClass
  • 8.BPhosphates, etc., with additional anions, without H2ODivision
  • 8.BNWith only large cations, (OH, etc.):RO4 = 0.33:1Group
  • 8.BN.05HydroxylhedyphaneSpecies

Group, growth & confusion

In the same group
10 members

Literature, links & citation

Citations
  1. 1985Dunn, Pete J., Rouse, Roland C., Nelen, Joseph A. (1985) Hydroxyl-bearing hedyphane from Långban Sweden. Geologiska Föreningen i Stockholm Förhandlingar, 107 (4) 325-327 doi:10.1080/11035898609453084DOI: 10.1080/11035898609453084
  2. 2010Pasero, Marco, Kampf, Anthony R., Ferraris, Cristiano, Pekov, Igor V., Rakovan, John, White, Timothy J. (2010) Nomenclature of the apatite supergroup minerals. European Journal of Mineralogy, 22 (2) 163-179 doi:10.1127/0935-1221/2010/0022-2022DOI: 10.1127/0935-1221/2010/0022-2022
  3. 2018Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2018) CNMNC Newsletter 45, New minerals and nomenclature modifications approved in 2018. Mineralogical Magazine, 82 (5) 1225-1232 doi:10.1180/mgm.2018.160DOI: 10.1180/mgm.2018.160
  4. 2019Biagioni, Cristian, Hålenius, Ulf, Pasero, Marco, Karlsson, Andreas, Bosi, Ferdinando (2019) Hydroxylhedyphane, Ca2Pb3(AsO4)3(OH), a new member of the apatite supergroup from Långban, Sweden. European Journal of Mineralogy, 31 (5) 1015-1024 doi:10.1127/ejm/2019/0031-2878 DOI: 10.1127/ejm/2019/0031-2878
  5. 2022(2022) Hydroxylhedyphane. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Hydroxylhedyphane — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/hydroxylhedyphane-47415},
  note      = {Accessed 2026-05-11}
}