Sinnerite

Cu6As4S9
IMA status
  • Approved
IMA symbol
Sin
Discovered
1964
IMA approved
1964
Also known as
  • IMA1964-020
  • Sinneriet
  • Tellit
  • +2 more

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°

13recorded occurrences
Source · OpenStreetMap

Safety & handling

Physical

Hardness
123456789104 – 4.5/ 10 MOHS
  1. 1Talc
  2. 2Gypsum
  3. 3Calcite
  4. 4Fluorite
  5. 5Apatite
  6. 6Orthoclase
  7. 7Quartz
  8. 8Topaz
  9. 9Corundum
  10. 10Diamond
Lustre
Metallic
Transparency
Opaque
Colour
Bronze · steel-grey · silver
Streak
grey-black
Cleavage
Poor/Indistinct

Crystallography

Crystal system
Triclinic
Space group
#1
Cell parameters
a = 9.103(2) Å · b = 9.860(3) Å · c = 9.111(2) Å
Cell angles
α = 90.27(2) ° · β = 109.53(2) ° · γ = 107.58(2) °
Ratio a:b:c
1 : 1.083 : 1.001
Unit cell volume
729.6 ų
Z
2
Twinning

Crystals are twinned complexly; principal laws are twin planes (010) and (110).

Type-locality form

A small crystal.

Comment

Small pseudo-orthorhombic subcell: a = 3.72, b = 3.70, c = 5.24 Å (Marumo & Nowacki, 1964).

Crystal structure

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
29CuCopperCopper663.546381.276
39.33%
33AsArsenicArsenic474.922299.688
30.91%
16SSulfurSulfur932.060288.540
29.76%
Total969.504100.00%

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

From IMA formula

Synonyms

  • IMA1964-020
  • Sinneriet
  • Tellit
  • Tellita
  • Tellite

In other languages

German
IMA 1964-020 · Sinnerit
Italian
Sinnerite

Classification

Strunz
10th ed.

2.GC.10

  • 2Sulfides and SulfosaltsClass
  • 2.GSulfarsenites, sulfantimonites, sulfbismuthitesDivision
  • 2.GCPoly-sulfarsenitesGroup
  • 2.GC.10SinneriteSpecies
Dana
8th ed.

03.06.14.01

  • 03SulfosaltsClass
  • 03.062 < ø < 2.49Type
  • 03.06.14— unnamed intermediate level —Group
  • 03.06.14.01SinneriteSpecies
CIM

5.1.1

  • 5Sulphosalts - Sulpharsenites and Sulphobismuthites (those containing Sn, Ge,or V are in Section 6)Class
  • 5.1Sulpharsenites etc. of CuGroup
  • 5.1.1SinneriteSpecies

Literature, links & citation

Citations
  1. 1964Marumo, F., Nowacki, W. (1964) The crystal structure of lautite and of sinnerite, a new mineral from the Lengenbach Quarry. Schweizerische Mineralogische und Petrographische Mitteilungen: 44: 439-454. https://rruff.info/rruff_1.0/uploads/SMPM44_439.pdf
  2. 1964Nowacki, W., Marumo, F., Takeuchi, Y. (1964) Untersuchungen an Sulfiden aus dem Binnatal (Kt. Wallis, Schweiz). Schweizerische Mineralogische und Petrographische Mitteilungen: 44(1): 5-9.
  3. 1972Makovicky, Emil, Skinner, Brian J. (1972) Studies of the sulfosalts of copper. II The crystallography and composition of sinnerite, Cu6As4S9. American Mineralogist, 57 (5-6) 824-834
  4. 1975Makovicky, Emil, Skinner, Brian J. (1975) Studies of the sulfosalts of copper. IV. Structure and twinning of sinnerite, Cu6As4S9. American Mineralogist, 60 (11-12) 998-1012
  5. 1999Harlov, Daniel E. (1999) Thermochemistry of Ag-Cu exchange equilibria between proustite, sinnerite, and pearceite: Constraints on Ag-Cu and As-Sb mixing in pyrargyrite-proustite. European Journal of Mineralogy, 11 (4) 709-720 doi:10.1127/ejm/11/4/0709DOI: 10.1127/ejm/11/4/0709
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Sinnerite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/sinnerite-3675},
  note      = {Accessed 2026-05-11}
}