Godovikovite

(NH4)Al(SO4)2
IMA status
  • Approved
IMA symbol
God
Discovered
1987
IMA approved
1987
Also known as
  • Godovikoviet
  • IMA1987-019
  • Unnamed (NH4-Al Sulphate)

Where it forms, where it's found

Geological setting

Burning coal mine dumps

Type locality
Kopeysk
  1. Chelyabinsk Oblast
  2. Russia

55.1167°, 61.6497°

21recorded occurrences
Source · OpenStreetMap

Physical

Hardness
123456789102/ 10 MOHS
  1. 1Talc
  2. 2Gypsum
  3. 3Calcite
  4. 4Fluorite
  5. 5Apatite
  6. 6Orthoclase
  7. 7Quartz
  8. 8Topaz
  9. 9Corundum
  10. 10Diamond
Transparency
Translucent
Colour
White · colorless in thin section
Streak
White
Fracture
Irregular/Uneven
Density
2.53 g/cm³

Optical

Optical type
Uniaxial (+)
Refractive index
1.572 – 1.581
Surface relief
Moderate
Principal indices
nω 1.572 · nε 1.581
Michel-Lévy diagramhighlighted lineδ = 0.0090
Attainable Michel-Lévy rangeΔ ∈ [0, t·δmax]90 nm1st 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°
Retardation90 nm
Order1st order
XPL colour

Crystallography

Crystal system
Trigonal
Space group
#90
Cell parameters
a = 4.75(1) Å · c = 8.30(1) Å
Z
1
Type-locality form

White, compact or porous chalky aggregates of fine hairs, 0.001 to 0.015 mm in size.

Chemical composition

Constituent elements
Mass composition breakdown
ElementAtoms At. mass g/mol Mass g/molMass share
8OOxygenOxygen815.999127.992
53.97%
16SSulfurSulfur232.06064.120
27.04%
13AlAluminiumAluminium126.98226.982
11.38%
7NNitrogenNitrogen114.00714.007
5.91%
1HHydrogenHydrogen41.0084.032
1.70%
Total237.133100.00%

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

From IMA formula

Synonyms

  • Godovikoviet
  • IMA1987-019
  • Unnamed (NH4-Al Sulphate)

In other languages

French
Godovikovite
German
Godovikovit · IMA 1987-019
Italian
Godovikovite
Portuguese
Godovikovita · IMA1987-019
Russian
Годовиковит

Classification

Strunz
10th ed.

7.AC.20

  • 7SulfatesClass
  • 7.ASulfates (selenates, etc.) without additional anions, without H2ODivision
  • 7.ACWith medium-sized and large cationsGroup
  • 7.AC.20GodovikoviteSpecies
Dana
8th ed.

28.03.05.02

  • 28Anhydrous Acid and Normal SulfatesClass
  • 28.03AXO4Type
  • 28.03.05— unnamed intermediate level —Group
  • 28.03.05.02GodovikoviteSpecies
CIM

25.11.18

  • 25SulphatesClass
  • 25.11Sulphates of Fe and other metalsGroup
  • 25.11.18GodovikoviteSpecies

Group, growth & confusion

Commonly confused with
1 mineral

Literature, links & citation

Citations
  1. 1988Shcherbakova, Y.P., Bazhenova, L.F., Chesnokov, B.V. (1988) Godovikovite – NH4(Al, Fe)(SO4)2, a new ammonium-bearing sulfate. Zapiski Vserossiyskogo Mineralogicheskogo Obshchestv: 117: 208-211 (in Russian).
  2. 1990Jambor, John L., Grew, Edward S. (1990) New Mineral Names. American Mineralogist, 75 (1-2) 240-246
  3. 2005(2005) Godovikovite. Handbook of Mineralogy. Mineralogical Society of America
  4. 2008Boujelben, M., Toumi, M., Mhiri, T. (2008) X-ray structure determination of NH4Al(SO4)2. Annales De Chimie - Science Des Materiaux: 33: 379-386.
  5. 2018Košek, F., Culka, A., Jehlička, J. (2018) Raman spectroscopic study of six synthetic anhydrous sulfates relevant to the mineralogy of fumaroles. Journal of Raman Spectroscopy, 49 (7). 1205-1216 doi:10.1002/jrs.5363DOI: 10.1002/jrs.5363
Cite this entry
@misc{mineral2026,
  author    = {Mineral Index editorial board},
  title     = {Godovikovite — Mineral Index},
  year      = {2026},
  url       = {https://mineralindex.org/minerals/godovikovite-1717},
  note      = {Accessed 2026-05-11}
}