Caoxite
A valid IMA mineral species
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About Caoxite
Formula:
Ca(C2O4) · 3H2O
Colour:
Colorless
Lustre:
Vitreous
Hardness:
2 - 2½
Specific Gravity:
1.87 (Calculated)
Crystal System:
Triclinic
Name:
For the acronym of "Centennial Anniversary Of X-rays" and also for Calcium Oxalate.
This page provides mineralogical data about Caoxite.
Unique Identifiers
Mindat ID:
6845
Long-form identifier:
mindat:1:1:6845:7
Similar Names
| Guixite | Valid as an unnamed mineral | Cu2(AsO4,SiO4)(OH,H2O) · H2O (?) |
IMA Classification of Caoxite
Approved
IMA Formula:
Ca(C2)6+O4·3H2O
Approval year:
1996
First published:
1997
Classification of Caoxite
10.AB.50
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
B : Oxalates
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
B : Oxalates
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 |
|---|---|---|
| Cao | 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 Caoxite
Vitreous
Transparency:
Transparent
Colour:
Colorless
Streak:
White
Hardness:
2 - 2½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Distinct/Good
{010}
{010}
Fracture:
Irregular/Uneven
Density:
1.87 g/cm3 (Calculated)
Optical Data of Caoxite
Type:
Biaxial (-)
RI values:
nα = 1.483(3) nβ = 1.516 nγ = 1.533(3)
2V:
Measured: 70° (2)
Max. Birefringence:
δ = 0.050
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:
Moderate
Dispersion:
relatively strong
Chemistry of Caoxite
Mindat Formula:
Ca(C2O4) · 3H2O
Element Weights:
Elements listed:
Crystallography of Caoxite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 6.097(1) Å, b = 7.145(1) Å, c = 8.434(1) Å
α = 76.54(1)°, β = 70.30(1)°, γ = 70.75(1)°
α = 76.54(1)°, β = 70.30(1)°, γ = 70.75(1)°
Ratio:
a:b:c = 0.853 : 1 : 1.18
Unit Cell V:
323.49 ų (Calculated from Unit Cell)
Z:
2
Crystal Structure
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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) |
|---|---|---|---|---|---|---|---|
| 0014895 | Caoxite | Basso R, Lucchetti G, Zefiro L, Palenzona A (1997) Caoxite, Ca(H2O)3(C2O4), a new mineral from the Cerchiara mine, northern Apennines, Italy Neues Jahrbuch fur Mineralogie, Monatshefte 1997 84-96 | 1997 | Cerchiara mine, Val di Vara, northern Apennines, Italy | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.92 Å | (m) |
| 5.26 Å | (m) |
| 5.52 Å | (vs) |
| 4.99 Å | (m) |
| 3.643 Å | (m) |
| 2.834 Å | (s) |
| 2.758 Å | (m) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 53 : Other minerals with taphonomic origins | <0.4 |
Type Occurrence of Caoxite
General Appearance of Type Material:
spherulitic and isolated aggregates, up to 0.5 mm across, consisting of colorless, stocky
crystals
crystals
Place of Conservation of Type Material:
Sezione di Mineralogia, Dipartimento di Scienze della Terra, Universita di Genova, Italy.
Geological Setting of Type Material:
veinlets cutting metamorphosed Mn–Ba-rich cherts in an obducted ophiolite.
Associated Minerals at Type Locality:
Synonyms of Caoxite
Other Language Names for Caoxite
Related Minerals - Strunz-mindat Grouping
| 10.AB. | Deveroite-(Ce) | Ce2(C2O4)3 · 10H2O |
| 10.AB. | Edwindavisite | Cu(C2O4)(NH3) |
| 10.AB.X | Falottaite | MnC2O4 · 3H2O |
| 10.AB. | Uroxite | [(UO2)2(C2O4)(OH)2(H2O)2] · H2O |
| 10.AB.05 | Katsarosite | Zn(C2O4) · 2H2O |
| 10.AB.05 | Andreybulakhite | Ni(C2O4) · 2H2O |
| 10.AB.05 | Humboldtine | Fe2+(C2O4) · 2H2O |
| 10.AB.05 | Lindbergite | Mn2+(C2O4) · 2H2O |
| 10.AB.10 | Glushinskite | Mg(C2O4) · 2H2O |
| 10.AB.15 | Moolooite | Cu(C2O4) · nH2O |
| 10.AB.20 | Stepanovite | NaMgFe3+(C2O4)3 · 8-9H2O |
| 10.AB.25 | Minguzzite | K3Fe3+(C2O4)3 · 3H2O |
| 10.AB.30 | Wheatleyite | Na2Cu(C2O4)2 · 2H2O |
| 10.AB.35 | Zhemchuzhnikovite | NaMgAl(C2O4)3 · 8H2O |
| 10.AB.40 | Weddellite | Ca(C2O4) · (2.5-x)H2O |
| 10.AB.45 | Whewellite | Ca(C2O4) · H2O |
| 10.AB.47 | Fiemmeite | Cu2(C2O4)(OH)2 · 2H2O |
| 10.AB.50 | Middlebackite | Cu2C2O4(OH)2 |
| 10.AB.52 | Metauroxite | (UO2)2(C2O4)(OH)2(H2O)2 |
| 10.AB.55 | Oxammite | (NH4)2(C2O4) · H2O |
| 10.AB.60 | Natroxalate | Na2(C2O4) |
| 10.AB.60 | Phoxite | (NH4)2Mg2(C2O4)(PO3OH)2(H2O)4 |
| 10.AB.60 | Carboferriphoxite | [(NH4)K(H2CO3)][Fe3+(HPO4)(H2PO4)(C2O4)] |
| 10.AB.60 | Ferriphoxite | [(NH4)2K(H2O)][Fe3+(HPO4)2(C2O4)] |
| 10.AB.65 | Coskrenite-(Ce) | Ce2(SO4)2(C2O4) · 8H2O |
| 10.AB.70 | Levinsonite-(Y) | (Y,Nd,La)Al(C2O4)(SO4)2 · 12H2O |
| 10.AB.75 | Zugshunstite-(Ce) | (Ce,Nd,La)Al(C2O4)(SO4)2 · 12H2O |
| 10.AB.80 | Novgorodovaite | Ca2(C2O4)Cl2 · 2H2O |
Fluorescence of Caoxite
None observed
Other Information
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 Caoxite
mindat.org URL:
https://www.mindat.org/min-6845.html
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Please feel free to link to this page.
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References for Caoxite
Reference List:
Basso, R., Lucchetti, G., Zefiro, L., Palenzona, A. (1997) Caoxite, Ca(H2O)3(C2O4), a new mineral from the Cerchiara mine, northern Apennines, Italy. Neues Jahrbuch für Mineralogie - Monatshefte, 1997 (2) 84-96 doi:10.1127/njmm/1997/1997/84
Jambor, John L., Grew, Edward S., Roberts, Andrew C. (1998) New mineral names. American Mineralogist, 83 (1) 185-189
Echigo, T., Kimata, M., Kyono, A., Shimizu, M., Hatta, T. (2005) Re-investigation of the crystal structure of whewellite [Ca(C2O4)·H2O] and the dehydration mechanism of caoxite [Ca(C2O4)·3H2O]. Mineralogical Magazine, 69 (1) 77-88 doi:10.1180/0026461056910235
Piilonen, P. C. (2005) New Mineral Names. American Mineralogist, 90 (8) 1466-1469 doi:10.2138/am.2005.448
Localities for Caoxite
Showing 1 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.
Italy (TL) | |
| Basso et al. (1997) +1 other reference |
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Cerchiara Mine, Borghetto di Vara, La Spezia Province, Liguria, Italy