Thermaerogenite

CuAl2O4
IMA status
  • Approved
IMA symbol
Tag
IMA approved
2018
Also known as
  • IMA2018-021
  • Thermaerogeniet

Where it forms, where it's found

Geological setting

Oxidizing fumaroles

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

Physical

Transparency
Transparent
Colour
Brown · yellow-brown · red-brown · brown-yellow · brown-red

May also be semitransparent

Tenacity
brittle
Cleavage
None Observed
Fracture
Conchoidal
Density
4.87 g/cm³

Crystallography

Crystal system
Isometric
Space group
#222
Cell parameters
a = 8.039(9) Å
Unit cell volume
530.1 ų
Type-locality form

Octahedral crystals( up to 0.02 mm in diameter), usually intergrown to constitute open-work clusters (up to 1 mm across)

Comment

Spacegroup Fd3m

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
8OOxygenOxygen415.99963.996
35.26%
29CuCopperCopper163.54663.546
35.01%
13AlAluminiumAluminium226.98253.964
29.73%
Total181.506100.00%

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

From IMA formula

Synonyms

  • IMA2018-021
  • Thermaerogeniet

In other languages

German
IMA 2018-021 · Thermaerogenit
Italian
Termaerogenite

Classification

Strunz
10th ed.

4.BB

  • 4OxidesClass
  • 4.BMetal: Oxygen = 3:4 and similarDivision
  • 4.BBWith only medium-sized cationsGroup
  • 4.BBThermaerogeniteSpecies

Group, growth & confusion

Literature, links & citation

Citations
  1. 1972COOLEY, RICHARD F., REED, JAMES S. (1972) Equilibrium Cation Distribution in NiAl2O4, CuAl2O4, and ZnAl2O4 Spinels. Journal of the American Ceramic Society, 55 (8). 395-398 doi:10.1111/j.1151-2916.1972.tb11320.xDOI: 10.1111/j.1151-2916.1972.tb11320.x
  2. 1973NAVROTSKY, A. (1973) Discussion of “Equilibrium Cation Distribution in NiAl2O4, CuAl2O4, and ZnAl2O4 Spinels”. Journal of the American Ceramic Society, 56 (2). 106-107 doi:10.1111/j.1151-2916.1973.tb12372.x-i1DOI: 10.1111/j.1151-2916.1973.tb12372.x-i1
  3. 2018Hålenius, U., Hatert, F., Pasero, M., Mills, S. J. (2018) CNMNC Newsletter No. 44, New minerals and nomenclature modifications approved in 2018. Mineralogical Magazine, 82 (4) 1015-1021 doi:10.1180/mgm.2018.148DOI: 10.1180/mgm.2018.148
  4. 2018Pekov, Igor, Sandalov, Fedor, Koshlyakova, Natalia, Vigasina, Marina, Polekhovsky, Yury, Britvin, Sergey, Sidorov, Evgeny, Turchkova, Anna (2018) Copper in Natural Oxide Spinels: The New Mineral Thermaerogenite CuAl2O4, Cuprospinel and Cu-Enriched Varieties of Other Spinel-Group Members from Fumaroles of the Tolbachik Volcano, Kamchatka, Russia. Minerals, 8 (11) 498 doi:10.3390/min8110498 DOI: 10.3390/min8110498
  5. 2020(2020) Thermaerogenite. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Thermaerogenite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/thermaerogenite-53041},
  note      = {Accessed 2026-05-11}
}