Orthogersdorffite

NiAsS
IMA status
  • Approved
IMA symbol
Gdf-Pca21
Also known as
  • Orthogersdorffiet

Where it forms, where it's found

3recorded occurrences
Source · OpenStreetMap

Safety & handling

Physical

Density
6.239 g/cm³

Crystallography

Crystal system
Orthorhombic
Space group
#29
Cell parameters
a = 5.685(3) Å · b = 5.685(3) Å · c = 5.685(3) Å
Ratio a:b:c
1 : 1.000 : 1.000
Z
4
Comment

Pseudocubic. Cell from sample R862 of Bayliss (1982); another sample, less close to the ideal formula, has a = 5.622 Å..

Crystal structure

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
33AsArsenicArsenic174.92274.922
45.22%
28NiNickelNickel158.69358.693
35.43%
16SSulfurSulfur132.06032.060
19.35%
Total165.675100.00%

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

From IMA formula

Synonyms

  • Orthogersdorffiet

In other languages

German
Gersdorffit-Pca2₁ · Orthogersdorffit
Italian
gersdorffite-Pca2₁

Classification

Strunz
10th ed.

2.EB.25

  • 2Sulfides and SulfosaltsClass
  • 2.EMetal Sulfides, M: S <= 1:2Division
  • 2.EBM:S = 1:2, with Fe, Co, Ni, PGE, etc.Group
  • 2.EB.25OrthogersdorffiteSpecies

Group, growth & confusion

Commonly confused with
2 minerals

Literature, links & citation

Citations
  1. 1982Bayliss, P. (1982) A further crystal structure refinement of gersdorffite. American Mineralogist, 67 (9-10) 1058-1064
  2. 2022Miyawaki, Ritsuro, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2022) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) – Newsletter 69. European Journal of Mineralogy, 34 (5) 463-468 doi:10.5194/ejm-34-463-2022 DOI: 10.5194/ejm-34-463-2022
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Orthogersdorffite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/orthogersdorffite-47658},
  note      = {Accessed 2026-05-11}
}