Lautite

CuAsS
IMA status
  • Approved
  • Grandfathered
IMA symbol
Ltt
Discovered
1881
Also known as
  • Lautiet

Where it forms, where it's found

Type locality
Rudolph shaft
  1. Lauta
  2. Marienberg
  3. Erzgebirgskreis
  4. Saxony
  5. Germany

50.6624°, 13.1448°

36recorded occurrences
Source · OpenStreetMap

Safety & handling

Physical

Hardness
123456789103.5/ 10 MOHS
  1. 1Talc
  2. 2Gypsum
  3. 3Calcite
  4. 4Fluorite
  5. 5Apatite
  6. 6Orthoclase
  7. 7Quartz
  8. 8Topaz
  9. 9Corundum
  10. 10Diamond
Transparency
Opaque
Colour
Black · steel-gray with reddish tone
Streak
Black
Cleavage

(001)

Density
4.91 g/cm³

Optical

Pleochroism
Weak

Crystallography

Crystal system
Orthorhombic
Space group
#71
Cell parameters
a = 11.347(4) Å · b = 3.7533(7) Å · c = 5.453(1) Å
Ratio a:b:c
1 : 0.331 : 0.481
Morphology

Short to long prismatic [100] crystals and tabular [001]; striated on (001) parallel to [100]. Also massive, fine granular or radiating.

Twinning

(110)

Crystal structure

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
33AsArsenicArsenic174.92274.922
43.94%
29CuCopperCopper163.54663.546
37.26%
16SSulfurSulfur132.06032.060
18.80%
Total170.528100.00%

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

From IMA formula

Synonyms

  • Lautiet

In other languages

German
Lautit
Spanish
Lautita
Italian
Lautite

Classification

Strunz
10th ed.

2.CB.40

  • 2Sulfides and SulfosaltsClass
  • 2.CMetal Sulfides, M: S = 1: 1 (and similar)Division
  • 2.CBWith Zn, Fe, Cu, Ag, etc.Group
  • 2.CB.40LautiteSpecies
Dana
8th ed.

02.12.08.01

  • 02SulfidesClass
  • 02.12AmBnXp, with (m+n):p = 1:2Type
  • 02.12.08— unnamed intermediate level —Group
  • 02.12.08.01LautiteSpecies
CIM

3.1.20

  • 3Sulphides, Selenides, Tellurides, Arsenides and Bismuthides (except the arsenides, antimonides and bismuthides of Cu, Ag and Au, which are included in Section 1)Class
  • 3.1Sulphides etc. of CuGroup
  • 3.1.20LautiteSpecies

Literature, links & citation

Citations
  1. 1881Frenzel, A. (1881) Mineralogisches. 6. Lautit. Tschermaks Mineralogische und Petrographische Mitteilungen: 3: 504-516.
  2. 1944Palache, Charles, Berman, Harry, Frondel, Clifford (1944) The System of Mineralogy (7th ed.) Vol. 1 - Elements, Sulfides, Sulfosalts, Oxides. John Wiley and Sons, New York.
  3. 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
  4. 1965Craig, D. C., Stephenson, N. C. (1965) The crystal structure of lautite, CuAsS. Acta Crystallographica, 19 (4) 543-547 doi:10.1107/s0365110x65003869DOI: 10.1107/s0365110x65003869
  5. 1978Chen, T.T., Dutrizac, J.E. (1978) Lautite and cadmium-rich sphalerite from the Ross mine, Hislop Township, Ontario. The Canadian Mineralogist: 16: 665-669.
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Lautite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/lautite-2348},
  note      = {Accessed 2026-05-11}
}