Caesiumpharmacosiderite

Where it forms, where it's found

Type locality: Wendy pit
Tambo Mine
Vicuña
Elqui Province
Coquimbo
Chile
-29.8121°, -69.9495°

2recorded occurrences

Source · OpenStreetMap

Safety & handling

Crystallography

Crystal system: Isometric
Space group: P-4 3m
Cell parameters: a = 7.9637(11) Å

Chemical composition

Constituent elements: Mass composition breakdown
Element Atoms At. mass g/mol Mass g/mol Mass share
8OOxygen Oxygen 20 15.999 319.980
35.04%
33AsArsenic Arsenic 3 74.922 224.766
24.62%
26FeIron Iron 4 55.845 223.380
24.46%
55CsCaesium Caesium 1 132.905 132.905
14.56%
1HHydrogen Hydrogen 12 1.008 12.096
1.32%
Total 913.127 100.00%
Mass share = atoms × atomic mass ÷ molar mass × 100
From IMA formula

Mass composition breakdown
Element	Atoms	At. mass g/mol	Mass g/mol	Mass share
8OOxygen	Oxygen	20	15.999	319.980	35.04%
33AsArsenic	Arsenic	3	74.922	224.766	24.62%
26FeIron	Iron	4	55.845	223.380	24.46%
55CsCaesium	Caesium	1	132.905	132.905	14.56%
1HHydrogen	Hydrogen	12	1.008	12.096	1.32%
	Total	913.127	100.00%

Synonyms

Caesiumpharmacosideriet
Cesiumpharmacosiderite
IMA2013-096

In other languages

German: Cäsiumpharmakosiderit · IMA 2013-096
Italian: caesiumpharmacosiderite

Classification

Strunz

10th ed.

8.CJ

8Phosphates, Arsenates, VanadatesClass
8.CPhosphates without additional anions, with H₂ODivision
8.CJWith only large cationsGroup
8.CJCaesiumpharmacosideriteSpecies

Group, growth & confusion

7 members

Literature, links & citation

Citations

2013Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2013) New minerals and nomenclature modifications approved in 2013. CNMNC Newsletter No 18. Mineralogical Magazine, 77 (8) 3249-3258 doi:10.1180/minmag.2013.077.8.15DOI: 10.1180/minmag.2013.077.8.15
2022(2022) Caesiumpharmacosiderite. Handbook of Mineralogy. Mineralogical Society of America

Cite this entry

@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Caesiumpharmacosiderite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/caesiumpharmacosiderite-46008},
  note      = {Accessed 2026-05-11}
}