Simonite

TlHgAs3S6
IMA status
  • Approved
IMA symbol
Smo
Discovered
1982
IMA approved
1982
Also known as
  • IMA1982-052
  • Simoniet

Where it forms, where it's found

Type locality
Allchar
  1. Ržanovo
  2. Kavadarci Municipality
  3. North Macedonia

41.1483°, 21.9536°

2recorded occurrences
Source · OpenStreetMap

Safety & handling

Physical

Colour
Red

Crystallography

Crystal system
Monoclinic
Cell parameters
a = 5.948(2) Å · b = 11.404(6) Å · c = 15.979(5) Å
Cell angles
β = 90.15(1) °
Ratio a:b:c
1 : 1.917 : 2.686
Z
4
Morphology

Occurs as inclusions in <m>rebulite</m>.

Comment

Space group P21/n.

Crystal structure

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
33AsArsenicArsenic374.922224.766
27.34%
81TlThalliumThallium1204.380204.380
24.86%
80HgMercuryMercury1200.592200.592
24.40%
16SSulfurSulfur632.060192.360
23.40%
Total822.098100.00%

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

From IMA formula

Impurities
  • Sb

Synonyms

  • IMA1982-052
  • Simoniet

In other languages

German
IMA 1982-052 · Simonit
Italian
Simonite

Classification

Strunz
10th ed.

2.GC.20

  • 2Sulfides and SulfosaltsClass
  • 2.GSulfarsenites, sulfantimonites, sulfbismuthitesDivision
  • 2.GCPoly-sulfarsenitesGroup
  • 2.GC.20SimoniteSpecies
Dana
8th ed.

03.07.10.01

  • 03SulfosaltsClass
  • 03.07ø = 2Type
  • 03.07.10Simonite GroupGroup
  • 03.07.10.01SimoniteSpecies
CIM

5.5.4

  • 5Sulphosalts - Sulpharsenites and Sulphobismuthites (those containing Sn, Ge,or V are in Section 6)Class
  • 5.5Sulpharsenites etc. of TlGroup
  • 5.5.4SimoniteSpecies

Literature, links & citation

Citations
  1. 1982Engel, P.; Nowacki, W.; Balić-Žunić, T.; Šćavnićar, S. (1982) The crystal structure of simonite, TlHgAs3S6. Zeitschrift für Kristallographie, 161 (1-4). 159-166 doi:10.1524/zkri.1982.161.14.159 DOI: 10.1524/zkri.1982.161.14.159
  2. 1984American Mineralogist (1984): 69: 211 (abs.).
  3. 1993Rieck, Branko (1993) Famous Mineral Localities: Allchar, Macedonia. The Mineralogical Record, 24 (6) 437-449
  4. 2005(2005) Simonite. Handbook of Mineralogy. Mineralogical Society of America
  5. 2007Roth, P. (2007): Minerals first discovered in Switzerland and minerals named after Swiss individuals, Kristallografik Verlag (Achberg Germany). (pp. 198-199)
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Simonite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/simonite-3667},
  note      = {Accessed 2026-05-11}
}