Wooldridgeite
A valid IMA mineral species
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About Wooldridgeite
Formula:
Na2CaCu2+2(P2O7)2 · 10H2O
Colour:
Blue-green
Lustre:
Vitreous
Hardness:
2 - 3
Specific Gravity:
2.279 (Calculated)
Crystal System:
Orthorhombic
Name:
Named after James Wooldridge (1923-1995), keen amateur mineralogist, micromounter and gemologist from Fernhill Heath, Worcestershire, U.K., who discovered the material.
The second diphosphate (pyrophosphate) to be discovered, probably a post-mining/post-collecting anthropogenic alteration.
NOTE: Synthetic woooldridgeite can be made simply using a solution of copper and calcium ions to which the commercial pyrophospate-based cleaning agent 'calgon' - used by collectors to remove clay minerals from specimen - has been added, and it is quite possible that the material from the type locality may have been cleaned using such a compound by the original collector (see also discussion in https://www.mindat.org/mesg-866193.html).
Man-made crystals also came on the market in China around 2026 (https://www.mindat.org/mesg-866193.html).
Compare canaphite, anastasenkoite; 'pyrophosphite', 'pyrocoproite', and 'arnhemite'.
See also UM1991-10-PO:BaCaHMgSr.
NOTE: Synthetic woooldridgeite can be made simply using a solution of copper and calcium ions to which the commercial pyrophospate-based cleaning agent 'calgon' - used by collectors to remove clay minerals from specimen - has been added, and it is quite possible that the material from the type locality may have been cleaned using such a compound by the original collector (see also discussion in https://www.mindat.org/mesg-866193.html).
Man-made crystals also came on the market in China around 2026 (https://www.mindat.org/mesg-866193.html).
Compare canaphite, anastasenkoite; 'pyrophosphite', 'pyrocoproite', and 'arnhemite'.
See also UM1991-10-PO:BaCaHMgSr.
Unique Identifiers
Mindat ID:
7371
Long-form identifier:
mindat:1:1:7371:0
IMA Classification of Wooldridgeite
Approved
IMA Formula:
Na2CaCu2+2(P2O7)2·10H2O
Approval year:
1997
First published:
1999
Approval history:
Note that the type material may be anthropogenic .
Classification of Wooldridgeite
8.FC.25
8 : PHOSPHATES, ARSENATES, VANADATES
F : Polyphosphates, Polyarsenates, [4]-Polyvanadates
C : Polyphosphates, etc., with H2O only
8 : PHOSPHATES, ARSENATES, VANADATES
F : Polyphosphates, Polyarsenates, [4]-Polyvanadates
C : Polyphosphates, etc., with H2O only
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 |
|---|---|---|
| Woo | 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 Wooldridgeite
Vitreous
Transparency:
Transparent
Colour:
Blue-green
Streak:
Very pale blue
Hardness:
2 - 3 on Mohs scale
Density:
2.279 g/cm3 (Calculated)
Optical Data of Wooldridgeite
Type:
Biaxial (+)
RI values:
nα = 1.508(1) nβ = 1.511(1) nγ = 1.517(1)
2V:
Measured: 76° , Calculated: 72°
Max. Birefringence:
δ = 0.009
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:
Low (negative)
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.
Dispersion:
none
Pleochroism:
Non-pleochroic
Chemistry of Wooldridgeite
Mindat Formula:
Na2CaCu2+2(P2O7)2 · 10H2O
Element Weights:
Crystallography of Wooldridgeite
Crystal System:
Orthorhombic
Class (H-M):
mm2 - Pyramidal
Space Group:
Fdd2
Cell Parameters:
a = 11.938(1) Å, b = 32.854(2) Å, c = 11.017(1) Å
Ratio:
a:b:c = 0.363 : 1 : 0.335
Unit Cell V:
4321.2 ų
Z:
8
Morphology:
Crystals have a rhombic-dipyramidal form, sometimes with subtly curved faces.
Crystal Structure
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Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
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CIF File Best | x | y | z | a | b | c
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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) |
|---|---|---|---|---|---|---|---|
| 0005593 | Wooldridgeite | Cooper M A, Hawthorne F C (1999) The crystal structure of wooldridgeite, Na2CaCu2(P2O7)2(H2O)10, a novel copper pyrophosphate mineral The Canadian Mineralogist 37 73-81 |  | 1999 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.23 Å | (30) |
| 6.52 Å | (100) |
| 4.05 Å | (40) |
| 3.255 Å | (40) |
| 2. 924 Å | (40) |
Type Occurrence of Wooldridgeite
General Appearance of Type Material:
Pale-blue crystals up to 2 mm across.
Place of Conservation of Type Material:
Manchester Museum, Manchester, England, N13200.
Empirical Formula of Type Material:
(Na1.96K0.03)Ca1.00(Cu1.85Mg0.04)P4.04O14(H2O)10
Chemical Analysis of Type Material:
| P2O5 | 39.37 % |
|---|---|
| CuO | 20.24 % |
| CaO | 7.73 % |
| Na2O | 8.33 % |
| K2O | 0.17 % |
| MgO | 0.24 % |
| H2O (calc) | 24.72 % |
| Total: | 100.8 % |
Associated Minerals at Type Locality:
Synonyms of Wooldridgeite
Other Language Names for Wooldridgeite
Dutch:Wooldridgeiet
German:Wooldridgeit
Woolridgeit
Woolridgeit
Russian:Вулдриджеит
Spanish:Wooldridgeita
Woolridgeita
Woolridgeita
Common Associates
Associations Based on Photo Data:
| 2 photos of Wooldridgeite associated with Calcite | CaCO3 |
| 2 photos of Wooldridgeite associated with Yarrowite | Cu9S8 |
| 1 photo of Wooldridgeite associated with Chalcopyrite | CuFeS2 |
| 1 photo of Wooldridgeite associated with Covellite | CuS |
| 1 photo of Wooldridgeite associated with Tennantite Subgroup | Cu6(Cu4C2+2)As4S12S |
Related Minerals - Strunz-mindat Grouping
| 8.FC. | Donowensite | Ca(H2O)3Fe3+2(V2O7)2 |
| 8.FC.X | Hylbrownite | Na3Mg(P3O10) · 12H2O |
| 8.FC.05 | Fianelite | Mn2+2((V,As)2O7) · 2H2O |
| 8.FC.05 | Rüdlingerite | Mn2+2V5+As5+O7 · 2H2O |
| 8.FC.10 | Canaphite | Na2Ca(P2O7) · 4H2O |
| 8.FC.15 | Pintadoite | Ca2(V2O7) · 9H2O |
| 8.FC.20 | 'Arnhemite' | (K,Na)4Mg2(P2O7)2 · 5H2O |
| 8.FC.30 | Kanonerovite | Na3Mn2+(P3O10) · 12H2O |
| 8.FC.35 | Mesaite | CaMn2+5(V2O7)3 · 12H2O |
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 Wooldridgeite
mindat.org URL:
https://www.mindat.org/min-7371.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Wooldridgeite
Reference List:
Hawthorne, F. C.; Cooper, M. A.; Green, D. I.; Starkey, R. E.; Roberts, A. C.; Grice, J. D. (1999) Wooldridgeite, Na2CaCu2+2(P2O7)2(H2O)10: A new mineral from Judkins Quarry, Warwickshire, England. Mineralogical Magazine, 63 (1). p.13-16. doi:10.1180/002646199548268 (see discussion on probable anthropogenic origin in https://www.mindat.org/mesg-866193.html)
Cooper, M. A., Hawthorne, F. C. (1999) The crystal structure of wooldridgeite, Na2CaCu2+2(P2O7)2(H2O)10, a novel copper pyrophosphate mineral. The Canadian Mineralogist, 37 (1) 73-81
Localities for Wooldridgeite
Showing 3 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.
Germany | |
| Kolitsch et al. (2019) |
UK | |
| Cooper et al. (1990) +1 other reference |
| Hawthorne et al. (1999) |
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Clara Mine, Oberwolfach, Ortenaukreis, Freiburg Region, Baden-Württemberg, Germany