Ardealite
A valid IMA mineral species - grandfathered
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About Ardealite
Transylvania (Ardeal), Romania
Formula:
Ca2(PO3OH)(SO4) · 4H2O
Colour:
Light yellow, yellow, brownish yellow, colourless
Lustre:
Dull, Earthy
Hardness:
1 - 1½
Specific Gravity:
2.30 - 2.34
Crystal System:
Monoclinic
Name:
Named by Josef Schadler and Franz Halla in 1931 for "Ardeal," the old Romanian name for Transylvania, where the type locality is situated.
Type Locality:
A secondary mineral resulting from the breakdown of bat guano in caves in reaction with calcite.
Unique Identifiers
Mindat ID:
321
Long-form identifier:
mindat:1:1:321:6
IMA Classification of Ardealite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Ca2(PO3OH)(S6+O4)·4H2O
First published:
1932
Classification of Ardealite
8.CJ.50
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
J : With only large cations
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
J : With only large cations
43.1.1.1
43 : COMPOUND PHOSPHATES, ETC.
1 : Acid Compound Phosphates, etc·
43 : COMPOUND PHOSPHATES, ETC.
1 : Acid Compound Phosphates, etc·
22.3.2
22 : Phosphates, Arsenates or Vanadates with other Anions
3 : Phosphates, arsenates or vanadates with sulphates
22 : Phosphates, Arsenates or Vanadates with other Anions
3 : Phosphates, arsenates or vanadates with sulphates
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Adl | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Ardealite
Dull, Earthy
Transparency:
Translucent
Comment:
Fine-grained mineral
Colour:
Light yellow, yellow, brownish yellow, colourless
Streak:
Pale yellow
Hardness:
1 - 1½ on Mohs scale
Tenacity:
Brittle
Cleavage:
None Observed
Density:
2.30 - 2.34 g/cm3 (Measured) 2.32 g/cm3 (Calculated)
Optical Data of Ardealite
Type:
Biaxial (-)
RI values:
nα = 1.531 nβ = 1.539 nγ = 1.546
2V:
Measured: 86°
Birefringence:
0.015
Max. Birefringence:
δ = 0.015
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
None to Very Low
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Pleochroism:
Non-pleochroic
Chemistry of Ardealite
Mindat Formula:
Ca2(PO3OH)(SO4) · 4H2O
Element Weights:
Crystallography of Ardealite
Crystal System:
Monoclinic
Class (H-M):
m - Domatic
Space Group:
Bb
Setting:
Cc
Cell Parameters:
a = 5.721 Å, b = 30.992 Å, c = 6.25 Å
β = 117.26°
β = 117.26°
Ratio:
a:b:c = 0.185 : 1 : 0.202
Unit Cell V:
985.08 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Crystals very thin platy, minute. Forms thin crusts and fine-grained powdery to clayey masses.
Comment:
Space Group of Cc is based on synthetic material.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
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Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0000666 | Ardealite | Sakae T, Nagata H, Sudo T (1978) The crystal structure of synthetic calcium phosphate - sulfate hydrate, Ca2HPO4SO4.4H2O, and its relation to brushite and gypsum American Mineralogist 63 520-527 |  | 1978 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.73 Å | (100) |
| 3.93 Å | (21) |
| 3.87 Å | (36) |
| 3.15 Å | (20) |
| 3.08 Å | (55) |
| 2.849 Å | (24) |
| 2.813 Å | (25) |
| 1.810 Å | (27) |
Comments:
ICDD 41-585
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 52 : Guano- and urine-derived minerals | <0.4 |
Geological Setting:
Limestone caves
Type Occurrence of Ardealite
General Appearance of Type Material:
Fine-grained, earthy to powdery masses.
Place of Conservation of Type Material:
The Natural History Museum, London, England, UK: #1933,87.
Geological Setting of Type Material:
Limestone cave
Associated Minerals at Type Locality:
Other Language Names for Ardealite
Related Minerals - Strunz-mindat Grouping
| 8.CJ. | Airdite | Sr(V4+O)2(PO4)2 · 4H2O |
| 8.CJ. | Dobšináite | Ca2Ca(AsO4)2 · 2H2O |
| 8.CJ. | Sainfeldite | Ca5(AsO4)2(AsO3OH)2 · 4H2O |
| 8.CJ. | Caesiumpharmacosiderite | CsFe3+4[(AsO4)3(OH)4] · 4H2O |
| 8.CJ. | Jeankempite | Ca5(AsO4)2(HAsO4)2 · 7H2O |
| 8.CJ.05 | Stercorite | (NH4)Na(PO3OH) · 4H2O |
| 8.CJ.10 | Swaknoite | (NH4)2Ca(PO3OH)2 · H2O |
| 8.CJ.10 | Mundrabillaite | (NH4)2Ca(PO3OH)2 · H2O |
| 8.CJ.15 | Nabaphite | NaBaPO4 · 9H2O |
| 8.CJ.15 | Nastrophite | Na(Sr,Ba)PO4 · 9H2O |
| 8.CJ.20 | Haidingerite | CaHAsO4 · H2O |
| 8.CJ.25 | Rhabdophane-(Y) | YPO4 · H2O |
| 8.CJ.25 | Vladimirite | Ca4(AsO4)2(AsO3OH) · 4H2O |
| 8.CJ.27 | 'Churchite-(Dy)' | (Dy,Sm,Gd,Nd)PO4 · 2H2O |
| 8.CJ.30 | Ferrarisite | Ca5(AsO4)2(HAsO4)2 · 9H2O |
| 8.CJ.35 | Fulbrightite | Ca(V4+O)2(As5+O4)2 · 4H2O |
| 8.CJ.35 | Machatschkiite | (Ca,Na)6(AsO4)(HAsO4)3(PO4,SO4) · 15H2O |
| 8.CJ.40 | Rauenthalite | Ca3(AsO4)2 · 10H2O |
| 8.CJ.40 | Phaunouxite | Ca3(AsO4)2 · 11H2O |
| 8.CJ.45 | Brockite | (Ca,Th,Ce)PO4 · H2O |
| 8.CJ.45 | Smirnovskite | (Th,Ca)PO4 · nH2O |
| 8.CJ.45 | Rhabdophane-(Ce) | Ce(PO4) · 0.6H2O |
| 8.CJ.45 | Rhabdophane-(La) | La(PO4) · H2O |
| 8.CJ.45 | Rhabdophane-(Nd) | Nd(PO4) · H2O |
| 8.CJ.45 | Tristramite | (Ca,U4+,Fe3+)(PO4,SO4) · 2H2O |
| 8.CJ.45 | Grayite | (Th,Pb,Ca)(PO4) · H2O |
| 8.CJ.45 | Štěpite | U(AsO3OH)2 · 4H2O |
| 8.CJ.47 | Vysokýite | U4+[AsO2(OH)2]4 · 4H2O |
| 8.CJ.50 | Churchite-(Y) | Y(PO4) · 2H2O |
| 8.CJ.50 | Brushite | Ca(PO3OH) · 2H2O |
| 8.CJ.50 | Pharmacolite | Ca(HAsO4) · 2H2O |
| 8.CJ.50 | 'Churchite-(Nd)' | Nd(PO4) · 2H2O |
| 8.CJ.55 | Mcnearite | NaCa5(AsO4)(HAsO4)4 · 4H2O |
| 8.CJ.60 | Dorfmanite | Na2(PO3OH) · 2H2O |
| 8.CJ.65 | Sincosite | Ca(V4+O)2(PO4)2 · 4H2O |
| 8.CJ.65 | Bariosincosite | Ba(V4+O)2(PO4)2 · 4H2O |
| 8.CJ.70 | Catalanoite | Na2(PO3OH) · 8H2O |
| 8.CJ.75 | Guérinite | Ca6(HAsO4)3(AsO4)2 · 10.5H2O |
| 8.CJ.85 | Ningyoite | (U,Ca,Ce)2(PO4)2 · 1-2H2O |
Other Information
Notes:
Commonly intermixed with Brushite and Gypsum.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Ardealite
mindat.org URL:
https://www.mindat.org/min-321.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Ardealite
Reference List:
Halla, F. (1931) Isomorphe Beziehungen und Doppelsalzbildung zwischen Gips und Brushit. Zeitschrift für Kristallographie, Mineralogie und Petrographie, 80 (1-6). p.349-352. doi:10.1524/zkri.1931.80.1.349
Sakae, Toshiro, Nagata, Hiroshi, Sudo, Toshio (1978) The crystal structure of synthetic calcium phosphate-sulfate hydrate, Ca2HPO4SO4·4H2O and its relation to brushite and gypsum. American Mineralogist, 63 (5-6) 520-527
Aslanian, Selma, Stoilova, Donka (1982) Étude de l'ardéalite, membre intermédiaire du système gypse-brushite. Bulletin de Minéralogie, 105 (6). 621-624 doi:10.3406/bulmi.1982.7644
Frost, Ray L.; Palmer, Sara J.; Pogson, Ross (2011) Thermal stability of the ‘cave’ mineral ardealite Ca2(HPO4)(SO4)·4H2O. Journal of Thermal Analysis and Calorimetry, 107 (2). 549-553 doi:10.1007/s10973-011-1458-0
Localities for Ardealite
Showing 42 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Australia | |
| R. Bottrill |
| Podgson RE |
| Helictite 13:19-33 |
Bahamas | |
| Onac et al. (2001) |
| Onac et al. (2001) +1 other reference | |
| Onac et al. (2001) | |
Bulgaria | |
| Mineralogical Society of America - ... |
| Mineralogical Society of America - ... |
Chile | |
| SEM-EDS by Igor V. Pekov |
France | |
| |
Hungary | |
| Geoda/2007/1 +1 other reference |
Italy | |
| Balenzano et al. (1984) +1 other reference |
| Balenzano et al. (1974) |
| Dell'Anna et al. (1989) |
| Dell'Anna et al. (1989) | |
| Audra et al. (2019) |
| Audra et al. (2019) |
Japan | |
| Anthony et al. (2000) |
Lebanon | |
| Kruszewski (2019) |
Malaysia | |
| Bridge et al. (1983) |
Mexico | |
| Forti (2006) |
Morocco | |
| Audra et al. (2021) |
Namibia | |
| Mineralogical Society of America - ... |
| Mineralogical Society of America - ... |
Romania | |
| Onac et al. (2007) +1 other reference |
| Dumitras D et al. (2004) |
| Halla (1931) +3 other references |
| Onac (2009) |
| Marincea et al. (2004) +1 other reference |
| Onac et al. (2003) |
Russia | |
| Sokol et al. (2022) |
Slovakia | |
| Cílek V. |
| Audra et al. (2019) |
South Africa | |
| Cairncross et al. (1995) |
| Miller et al. (2016) |
South Korea | |
| Jun +4 other references |
Spain | |
| B. Onac et al (2009) |
| Onac et al. (2005) |
| Onac et al. (2005) |
| Calvo Rebollar et al. (2022) |
Venezuela | |
| Urbani (1996) |
| Franco Urbani (2009) |
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Moorba Cave, Jurien Bay, Dandaragan Shire, Western Australia, Australia