Where it forms, where it's found
- Type locality
- Francisco de Vergara
- Oficina María Elena
- María Elena
- Tocopilla Province
- Antofagasta
- Chile
11recorded occurrences
Physical
- Transparency
- Translucent
- Colour
- White · pale yellow
- Cleavage
- Perfect
(010)
- Density
- 2.85 g/cm³
Optical
- Optical type
- Biaxial (+)
- Refractive index
- 1.469 – 1.491
- Principal indices
- nα 1.469 · nβ 1.473 · nγ 1.491
- Dispersion
- relatively weak
- Notes
2V(meas.) = Large.
Δ = 0Δmax
PPLpleochroism per grain
XPLindependent extinctions · rotate the stage
PPLpleochroism only · colour blends on rotation
XPLinterference colour · extinct every 90°
Retardation220 nm
Order1st order
XPL colour
Crystallography
- Cell parameters
- a = 12.25 Å · b = 13.95 Å · c = 15.95 Å
- Ratio a:b:c
- 1 : 1.139 : 1.302
- Comment
Point Group: n.d. Space Group: n.d. synthetic
Chemical composition
In other languages
- German
- Meta-Alunogen
- Italian
- Meta-alunogeno
Classification
Strunz
10th ed.7.CB.45
- 7SulfatesClass
- 7.CSulfates (selenates, etc.) without additional anions, with H2ODivision
- 7.CBWith only medium-sized cationsGroup
- 7.CB.45Meta-alunogenSpecies
Dana
8th ed.29.08.07.01
- 29Hydrated Acid and Normal SulfatesClass
- 29.08A2(XO4)3·H2OType
- 29.08.07— unnamed intermediate level —Group
- 29.08.07.01Meta-alunogenSpecies
CIM
—25.6.6
- 25SulphatesClass
- 25.6Sulphates of Al and TlGroup
- 25.6.6Meta-alunogenSpecies
Group, growth & confusion
Literature, links & citation
Citations
- 1942S. G. Gordon (1942) Results of the chilean mineralogical expedition of 1938. Part VII. The crystallography of alunogen, meta-alunogen and pickeringite. Notula Naturae Academy of Science Philadelphia, Not. Nat., no. 101.
- 1943Fleischer, M. (1943) New mineral names. American Mineralogist: 28: 61-64.
- 1951Palache, Charles; Berman, Harry; Frondel, Clifford (1951) The System of Mineralogy (7th ed.) Vol. 2 - Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. John Wiley and Sons.
- 2017Kahlenberg, V., Braun, D.E., Krüger, H., Schmidmair, D., Orlova, M. (2017): Temperature- and moisture-dependent studies on alunogen and the crystal structure of meta-alunogen determined from laboratory powder diffraction data. Physics and Chemistry of Minerals, 4, 95-107.
- 2021(2021) Meta-alunogen. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
author = {Mineral Index editorial board},
title = {Meta-alunogen — Mineral Index},
year = {2026},
url = {https://mineralindex.org/minerals/meta-alunogen-2660},
note = {Accessed 2026-05-11}
}