Eleomelanite

(K2Pb)Cu4O2(SO4)4
IMA status
  • Approved
IMA symbol
Elm
IMA approved
2016
Also known as
  • Eleomelaniet
  • IMA2015-118

Where it forms, where it's found

Geological setting

Fumarole

Type locality
Arsenatnaya fumarole
  1. Second scoria cone
  2. Northern Breakthrough (North Breach)
  3. Great Fissure eruption (Main Fracture)
  4. Tolbachik Volcanic field
  5. Milkovsky District
  6. Kamchatka Krai
  7. Russia

55.6833°, 160.2333°

1recorded occurrences
Source · OpenStreetMap

Safety & handling

Physical

Transparency
Translucent
Colour
Black
Density
3.790 g/cm³

Optical

Optical type
Biaxial (-) · 2V measured = 60°
Refractive index
1.646 – 1.734
Surface relief
High
Principal indices
nα 1.646 · nβ 1.715 · nγ 1.734
Michel-Lévy diagramhighlighted lineδ = 0.0880
Attainable Michel-Lévy rangeΔ ∈ [0, t·δmax]880 nm2nd order
Δ = 0Δmax
Thin-section mosaic70 grains · random 3D orientations
PPLpleochroism per grain
XPLindependent extinctions · rotate the stage
Interference simulatorsingle grain · PPL ↔ XPL
PPLpleochroism only · colour blends on rotation
XPLinterference colour · extinct every 90°
Retardation880 nm
Order2nd order
XPL colour

Crystallography

Crystal system
Monoclinic
Cell parameters
a = 9.3986(3) Å · b = 4.8911(1) Å · c = 18.2293(5) Å
Cell angles
β = 104.409(3) °
Ratio a:b:c
1 : 0.520 : 1.940
Type-locality form

Interrupted crusts up to 6 mm across and up to 0.3 mm thick consisting of equant, prismatic, or tabular crystals or grains up to 0.3 mm.

Comment

P21/n

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
8OOxygenOxygen1815.999287.982
30.13%
29CuCopperCopper463.546254.184
26.59%
82PbLeadLead1207.200207.200
21.68%
16SSulfurSulfur432.060128.240
13.42%
19KPotassiumPotassium239.09878.196
8.18%
Total955.802100.00%

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

From IMA formula

Synonyms

  • Eleomelaniet
  • IMA2015-118

In other languages

German
Eleomelanit · IMA 2015-118

Classification

Strunz
10th ed.

7.BC.52

  • 7SulfatesClass
  • 7.BSulfates (selenates, etc.) with additional anions, without H2ODivision
  • 7.BCWith medium-sized and large cationsGroup
  • 7.BC.52EleomelaniteSpecies

Literature, links & citation

Citations
  1. 2016(2016)
  2. 2016Hålenius, U., Hatert, F., Pasero, M., Mills, S.J. (2016) New minerals and nomenclature modifications approved in 2016, CNMNC Newsletter no 30. Mineralogical Magazine, 80 (2) 407-413 doi:10.1180/minmag.2016.080.081DOI: 10.1180/minmag.2016.080.081
  3. 2020Pekov, Igor V., Zubkova, Natalia V., Agakhanov, Atali A., Chukanov, Nikita V., Belakovskiy, Dmitry I., Sidorov, Evgeny G., Britvin, Sergey N., Turchkova, Anna G., Pushcharovsky, Dmitry Yu. (2020) Eleomelanite, (K2Pb)Cu4O2(SO4)4, a new mineral species from the Tolbachik Volcano, Kamchatka, Russia. The Canadian Mineralogist, 58 (5) 625-636 doi:10.3749/canmin.2000032DOI: 10.3749/canmin.2000032
  4. 2022(2022) Eleomelanite. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Eleomelanite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/eleomelanite-47609},
  note      = {Accessed 2026-05-11}
}