Marumoite

Pb32As40S92
IMA status
  • Approved
IMA symbol
Mrm
IMA approved
1998
Also known as
  • IMA1998-004
  • Marumoiet

Where it forms, where it's found

Type locality
Lengenbach Quarry
  1. Fäld
  2. Binn
  3. Goms
  4. Valais
  5. Switzerland

46.3653°, 8.2205°

1recorded occurrences
Source · OpenStreetMap

Safety & handling

Physical

Transparency
Opaque
Colour
Lead grey

Crystallography

Crystal system
Monoclinic
Space group
#9
Cell parameters
a = 8.368 Å · b = 115.75 Å · c = 7.903 Å
Cell angles
β = 90.11 °
Ratio a:b:c
1 : 13.832 : 0.944
Unit cell volume
7654.8 ų

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
82PbLeadLead32207.2006630.400
52.72%
33AsArsenicArsenic4074.9222996.880
23.83%
16SSulfurSulfur9232.0602949.520
23.45%
Total12576.800100.00%

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

From IMA formula

Synonyms

  • IMA1998-004
  • Marumoiet

In other languages

German
IMA 1998-004 · Marumoit
Italian
Marumoite
Japanese
丸茂鉱

Classification

Strunz
10th ed.

2.HC.05g

  • 2Sulfides and SulfosaltsClass
  • 2.HSulfosalts of SnS archetypeDivision
  • 2.HCWith only PbGroup
  • 2.HC.05gMarumoiteSpecies

Literature, links & citation

Citations
  1. 1983Ozawa, T. and Takeuchi, Y. (1983) A new Pb-As sulfosalt having a long periodicity from Lengenbach. Mineralogical Society of Japan Annual Meeting 1983, D4 (abstract) .
  2. 1999Lapaire, Jacques (1999) Une curiosité: Les sulfosels de la mine du Lengenbach, Valais (Suisse) Le Règne Minéral, 5 (30) 33-41
  3. 2005Shimizu M., Ishizaki Y., Honma T., Matsubara S., Miyawaki R. (2005) Mineral Deposit Research: Meeting the Global Challenge, 1, 695-697.
  4. 2005Shimizu, M., Ishizaki, Y., Honma, T., Matsubara, S., Miyawaki, R. (2005) Dufrenoysite and marumoite from the Okoppe Mine, Japan. 8th Biennal SGA Meeting, Beijing, August 18-21, 2005, Poster #100.
  5. 2021(2021) Marumoite. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Marumoite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/marumoite-26404},
  note      = {Accessed 2026-05-11}
}