Where it forms, where it's found
- Geological setting
Alteration of pyrite and decaying organic material (Hyrex excreta).
- Type locality
- Lone Creek Falls cave
- Lone Creek Falls
- Sabie
- Thaba Chweu Local Municipality
- Ehlanzeni District Municipality
- Mpumalanga
- South Africa
-25.1022°, 30.7092°
10recorded occurrences
Physical
- Transparency
- Transparent · Translucent
- Colour
- Orange-Yellow
- Density
- 2.31 g/cm³
Optical
- Optical type
- Biaxial
- Refractive index
- 1.595 – 1.607
- Surface relief
- Moderate
- Principal indices
- nα 1.595 · nγ 1.607
- Pleochroism
- Weak
X= pale yellow Z'= dark yellow
- Dispersion
- r > v or r < v
Δ = 0Δmax
PPLpleochroism per grain
XPLindependent extinctions · rotate the stage
PPLpleochroism only · colour blends on rotation
XPLinterference colour · extinct every 90°
Retardation120 nm
Order1st order
XPL colour
Crystallography
- Cell parameters
- a = 9.36 Å · b = 9.15 Å · c = 52.61 Å
- Cell angles
- α = 88.15 ° · β = 90 ° · γ = 118.36 °
- Ratio a:b:c
- 1 : 0.978 : 5.621
- Morphology
Powdery aggregates of pseudo-hexagonal plates.
- Comment
point group _1 or 1; space group P_1 or P1
Chemical composition
Synonyms
- Clairiet
- IMA1982-093
In other languages
- German
- Clairit · IMA 1982-093
- Italian
- Clairite
- Chinese
- 科拉里矾
Classification
Strunz
10th ed.7.DF.55
- 7SulfatesClass
- 7.DSulfates (selenates, etc.) with additional anions, with H2ODivision
- 7.DFWith large and medium-sized cationsGroup
- 7.DF.55ClairiteSpecies
Dana
8th ed.31.10.08.01
- 31Hydrated Sulfates Containing Hydroxyl or HalogenClass
- 31.10MiscellaneousType
- 31.10.08— unnamed intermediate level —Group
- 31.10.08.01ClairiteSpecies
CIM
—25.11.15
- 25SulphatesClass
- 25.11Sulphates of Fe and other metalsGroup
- 25.11.15ClairiteSpecies
Literature, links & citation
Citations
- 1984Martini, J.E.J. (1984) Lonecreekite, sabieite, and clairite, new secondary ammonium ferric-iron sulfates from Lone Creek Fall cave, near Sabie, eastern Transvaal. Annals of the Geological Survey (South Africa): 17: 29-34.
- 1986Dunn, Pete J., Chao, George Y., Fitzpatrick, Joan J., Langley, Richard H., Fleischer, Michael, Zilczer, Janet A. (1986) New Mineral Names. American Mineralogist, 71 (1-2). 227-232
- 1997Daltry, V. D. C. (1997) Mineralogy of South Africa: Type-Mineral Species and Type-Mineral Names. Handbook 15. Geological Survey of South Africa
- 2005(2005) Clairite. Handbook of Mineralogy. Mineralogical Society of America
- 2020Košek, F., Edwards, H.G.M., Jehlička, J. (2020) Raman spectroscopic vibrational analysis of the complex iron sulfates clairite, metavoltine, and voltaite from the burning coal dump Anna I, Alsdorf, Germany. Journal of Raman Spectroscopy, 51 (9) 1454-1461 doi:10.1002/jrs.5625DOI: 10.1002/jrs.5625
Cite this entry
@misc{mineral2026,
author = {Mineral Index editorial board},
title = {Clairite — Mineral Index},
year = {2026},
url = {https://mineralindex.org/minerals/clairite-1056},
note = {Accessed 2026-05-11}
}