Where it forms, where it's found
- Geological setting
marbles; a secondary phase
- Type locality
- Penrice marble quarry
- Penrice
- Barossa Council
- South Australia
- Australia
-34.4817°, 139.0467°
2recorded occurrences
Physical
- Density
- 2.12 g/cm³
Optical
- Optical type
- Biaxial (+) · 2V measured = 10 – 20°
- Refractive index
- 1.502 – 1.58
- Surface relief
- Moderate
- Principal indices
- nα 1.502 · nβ 1.503 · nγ 1.58
- Birefringence
- n<sub>γ</sub> was not measured in the type material, but is estimated here as derived from the 2V° measurement. The birefringence is subsequently calculated from this estimated n<sub>γ</sub>, and so should be considered as estimate as well.
- Notes
nγ not determined due to extreme thinness of the crystals; orientation: X = b, Y ≈ c, Z ≈ a* An estimate of nγ is calculated here from the observations of B(+) and 2V° = 10°-20°.
Δ = 0Δmax
PPLpleochroism per grain
XPLindependent extinctions · rotate the stage
PPLpleochroism only · colour blends on rotation
XPLinterference colour · extinct every 90°
Retardation780 nm
Order2nd order
XPL colour
Crystallography
- Space group
- P21/c
- Cell parameters
- a = 13.478(3) Å · b = 9.971(2) Å · c = 6.999(1) Å
- Cell angles
- β = 97.20(3) °
- Ratio a:b:c
- 1 : 0.740 : 0.519
- Type-locality form
platy crystals, up to 100 μm in diameter and 1-2 μm thick, forming rod-like aggregates
Chemical composition
Synonyms
- Penriceiet
In other languages
- German
- IMA 2021-068 · Penriceit
Classification
Strunz
10th ed.8.DM
- 8Phosphates, Arsenates, VanadatesClass
- 8.DPhosphates, etc. with additional anions, with H2ODivision
- 8.DMWith large and medium-sized cations, (OH, etc.):RO4 > 2:1Group
- 8.DMPenriceiteSpecies
Group, growth & confusion
Literature, links & citation
Citations
- 2022Elliott, P., Grey, I.E., Macrae, C.M., Kampf, A.R., Davidson, C. (2022): Penriceite, [Mg(H2O)6][Na(H2O)2Al3(PO4)2F6]·H2O, the F-analogue of aldermanite, from the Penrice marble quarry. Australian Journal of Mineralogy, 23(1), 5-12.
- 2022(2022) Penriceite. Handbook of Mineralogy. Mineralogical Society of America
Cite this entry
@misc{mineral2026,
author = {Mineral Index editorial board},
title = {Penriceite — Mineral Index},
year = {2026},
url = {https://mineralindex.org/minerals/penriceite-55685},
note = {Accessed 2026-05-11}
}