Where it forms, where it's found
- Geological setting
Manganese pod
- Type locality
- Torr Works Quarry
- Cranmore
- Mendip
- Somerset
- England
- UK
51.1998°, -2.4379°
1recorded occurrences
Safety & handling
Physical
- Transparency
- Translucent
- Colour
- Pale orange-brown
- Streak
- White
- Cleavage
- Perfect
on (100)
- Density
- 7.838 g/cm³
Optical
- Optical type
- Uniaxial
- Reflectance R%
- (14.6) 470, (13.6) 546, (13.4) 589, (13.2) 650
- Notes
Mean refractive index (calculated at 589 nm) is 2.106
Reflected-light panel
R̄ 13.7 %isotropic · single curve
Specimen
White reference
Crystallography
- Space group
- I4/mmm
- Cell parameters
- a = 4.065(1) Å · c = 12.631(7) Å
- Unit cell volume
- 208.7 ų
- Z
- 2
- Type-locality form
Found in a small cavity in ‘hydrocerussite’ from a manganese pod. Three specimens of the species have been identified (2018), one of which has been sampled to provide a few tiny fragments. The original specimen BM 1970,110 is at the NHM and the other two
- Comment
Aurivillius structure type
Crystal structure
Chemical composition
Synonyms
- IMA2011-091
- Rumseyiet
In other languages
- German
- IMA 2011-091 · Rumseyit
- Italian
- rumseyite
Classification
Strunz
10th ed.3.DC.52
- 3HalidesClass
- 3.DOxyhalides, hydroxyhalides and related double halidesDivision
- 3.DCWith Pb (As,Sb,Bi), without CuGroup
- 3.DC.52RumseyiteSpecies
Group, growth & confusion
Literature, links & citation
Citations
- 2012Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2012) New minerals and nomenclature modifications approved in 2012. CNMNC Newsletter No 13. Mineralogical Magazine, 76 (3) 807-817 doi:10.1180/minmag.2012.076.3.26 DOI: 10.1180/minmag.2012.076.3.26
- 2012Siidra, O. I., Turner, R. W., Krivovichev, S. V., Spratt, J. (2012) Rumseyite, [Pb2OF]Cl – fluoroxychloride mineral with the parent crystal structure for layered lead oxychlorides. Acta Crystallographica Section A Foundations of Crystallography, 68. doi:10.1107/s0108767312096201DOI: 10.1107/s0108767312096201
- 2012Turner, R. W., Siidra, O. I., Krivovichev, S. V., Stanley, C. J., Spratt, J. (2012) Rumseyite, [Pb2OF]Cl, the first naturally occurring fluoroxychloride mineral with the parent crystal structure for layered lead oxychlorides. Mineralogical Magazine, 76 (5) 1247-1255 doi:10.1180/minmag.2012.076.5.11 DOI: 10.1180/minmag.2012.076.5.11
- 2015(2015) Rumseyite. Handbook of Mineralogy. Mineralogical Society of America
- 2023Kasatkin, Anatoly V., Siidra, Oleg I., Nestola, Fabrizio, Pekov, Igor V., Agakhanov, Atali A., Koshlyakova, Natalia N., Chukanov, Nikita V., Nazarchuk, Evgeny V., Molinari, Simone, Rossi, Manuela (2023) Napoliite, Pb2OFCl, a new mineral from Vesuvius volcano, and its relationship with dimorphous rumseyite. Mineralogical Magazine, 87 (5) 711-718 doi:10.1180/mgm.2023.43DOI: 10.1180/mgm.2023.43
Cite this entry
@misc{mineral2026,
author = {Mineral Index editorial board},
title = {Rumseyite — Mineral Index},
year = {2026},
url = {https://mineralindex.org/minerals/rumseyite-42723},
note = {Accessed 2026-05-11}
}