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Weddellite

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Formula:
Ca(C
 
2
O
 
4
) · 2H
 
2
O
System:TetragonalColour:Colourless, white, ...
Hardness:4
Name:Named after its discovery locality, the Weddell Sea, Antarctica.


Authigenic in bottom sediments and peat; in calcareous lacustrine sediments; also formed by reaction of calcite with oxalic acid derived from lichens; also from solutions derived from bat guano. Known as component of human urinary stones.

NOTE: Cleaning with oxalic acid will lead to crystallisation of whewellite or weddellite if Ca-bearing soluble species are present on the specimen.

Classification of Weddellite

IMA status:Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID:9/A.01-20
Nickel-Strunz 10th (pending) edition ID:10.AB.40

10 : ORGANIC COMPOUNDS
A : Salts of organic acids
B : Oxalates
Dana 8th edition ID:50.1.2.1

50 : ORGANIC COMPOUNDS
1 : Oxalates
Hey's CIM Ref.:31.1.6

31 : Oxalates, Citrates, Mellitates and Acetates
1 : Oxalates
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Type Occurrence of Weddellite

Type Locality:Weddell Sea, Western Antarctica, Antarctica
General Appearance of Type Material:Tiny isolated crystals
Place of Conservation of Type Material:The Natural History Museum, London, England: #1936,975 to 1936,977.
Year of Discovery:1942
Geological Setting of type material:Bottom muds of a arctic sea.

Occurrences of Weddellite

Geological Setting:Authigenic in bottom sediments and peat; in calcareous lacustrine sediments; also formed by reaction of calcite with oxalic acid derived from lichens; also from solutions derived from bat guano.

Physical Properties of Weddellite

Diaphaneity (Transparency):Transparent
Colour:Colourless, white, yellowish brown to brown; colourless in transmitted light.
Hardness (Mohs):4
Cleavage:None Observed
Fracture:Sub-Conchoidal
Density (measured):1.94 g/cm3
Density (calculated):1.962 g/cm3

Crystallography of Weddellite

Crystal System:Tetragonal
Class (H-M):4/m - Dipyramidal
Space Group:I4/m
Cell Parameters:a = 12.371Å, c = 7.357Å
Ratio:a:c = 1 : 0.595
Unit Cell Volume:V 1,125.93 ų (Calculated from Unit Cell)
Z:8
Morphology:Crystals commonly isolated, with {011}, elongated [010], terminated by {001}; commonly corroded.
Twinning:Single or multiple twins possibly noted.
X-Ray Powder Diffraction:
Image Loading

Radiation - Copper Kα
Data Set:
Horizontal Axis: ° to ° Vertical Axis: % Source Data: Filtered Data:
Data courtesy of RRUFF project at University of Arizona, used with permission.

Optical Data of Weddellite

Type:Uniaxial (+)
RI values: nω = 1.523 nε = 1.544
Maximum Birefringence:δ = 0.021

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Low

Chemical Properties of Weddellite

Formula:
Ca(C
 
2
O
 
4
) · 2H
 
2
O
Simplified for copy/paste:Ca(C2O4)·2H2O
Essential elements:C, Ca, H, O
All elements listed in formula:C, Ca, H, O
Common Impurities:ORG

Relationship of Weddellite to other Species

Common Associates:
WhewelliteUreaPhosphammiteAphthitalite
Related Minerals - Nickel-Strunz Grouping):

- +
10.AB.05Humboldtine
Fe
2+
 
(C
 
2
O
 
4
) · 2H
 
2
O
10.AB.05Lindbergite
Mn
2+
 
(C
 
2
O
 
4
) · 2H
 
2
O
10.AB.10Glushinskite
Mg(C
 
2
O
 
4
) · 2H
 
2
O
10.AB.15Moolooite
Cu(C
 
2
O
 
4
) · 0.4H
 
2
O
10.AB.20Stepanovite
NaMgFe
3+
 
(C
 
2
O
 
4
)
 
3
· 8-9H
 
2
O
10.AB.25Minguzzite
K
 
3
Fe
3+
 
(C
 
2
O
 
4
)
 
3
· 3H
 
2
O
10.AB.30Wheatleyite
Na
 
2
Cu(C
 
2
O
 
4
)
 
2
· 2H
 
2
O
10.AB.35Zhemchuzhnikovite
NaMg(Fe
3+
 
,Al)(C
 
2
O
 
4
)
 
3
· 8H
 
2
O
10.AB.45Whewellite
Ca(C
 
2
O
 
4
) · H
 
2
O
10.AB.50Caoxite
Ca(C
 
2
O
 
4
) · 3H
 
2
O
10.AB.55Oxammite
(NH
 
4
)
 
2
(C
 
2
O
 
4
) · H
 
2
O
10.AB.60Natroxalate
Na
 
2
(C
 
2
O
 
4
)
10.AB.65Coskrenite-(Ce)
(Ce,Nd,La)
 
2
(C
 
2
O
 
4
)(SO
 
4
)
 
2
· 12H
 
2
O
10.AB.70Levinsonite-(Y)
(Y,Nd,La)Al(C
 
2
O
 
4
)(SO
 
4
)
 
2
· 12H
 
2
O
10.AB.75Zugshunstite-(Ce)
(Ce,Nd,La)Al(C
 
2
O
 
4
)(SO
 
4
)
 
2
· 12H
 
2
O
10.AB.80Novgorodovaite
Ca
 
2
(C
 
2
O
 
4
)Cl
 
2
· 2H
 
2
O
Related Minerals - Hey's Index Grouping:

- +
31.1.1Oxammite
(NH
 
4
)
 
2
(C
 
2
O
 
4
) · H
 
2
O
31.1.2Moolooite
Cu(C
 
2
O
 
4
) · 0.4H
 
2
O
31.1.3Wheatleyite
Na
 
2
Cu(C
 
2
O
 
4
)
 
2
· 2H
 
2
O
31.1.4Glushinskite
Mg(C
 
2
O
 
4
) · 2H
 
2
O
31.1.5Whewellite
Ca(C
 
2
O
 
4
) · H
 
2
O
31.1.7Humboldtine
Fe
2+
 
(C
 
2
O
 
4
) · 2H
 
2
O
31.1.8Stepanovite
NaMgFe
3+
 
(C
 
2
O
 
4
)
 
3
· 8-9H
 
2
O
31.1.9Zhemchuzhnikovite
NaMg(Fe
3+
 
,Al)(C
 
2
O
 
4
)
 
3
· 8H
 
2
O
31.1.10Minguzzite
K
 
3
Fe
3+
 
(C
 
2
O
 
4
)
 
3
· 3H
 
2
O

Other Names for Weddellite

Synonyms:
Hydrated Calcium Oxalate
Other Languages:
German:Weddellit
Russian:Уэдделлит
Spanish:Weddellita

Other Information

Other Information:Dehydrates to Whewellite upon exposure to air. Insoluble in water.
Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Weddellite

Reference List:

- +
Nakano (1923) Journal of BiochemistryP: 2: 437.

Hammarsten (1929) Comptes rendu des trav. lab. Carlsberg: 17: 1.

Bannister and Hey (1936) Discovery Reports: 13: 60 (as Hydrated Calcium Oxalate).

Frondel and Prien (1942) Science: 95: 431.

Lecompte, Pobeguin, and Wyart (1943) Rendus de l’Académie des sciences de Paris: 216: 808.

Pobeguin (1943) rendu de l’Académie des sciences de Paris: 216: 500.

Prien and Frondel (1947) Journal of urology: 57: 949 (includes study of urinary calculi).

Palache, Charles, Harry Berman & Clifford Frondel (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana Yale University 1837-1892, Volume II. John Wiley and Sons, Inc., New York, 7th edition, revised and enlarged, 1124 pp.: 1101-1102.

Acta Crystallographica: 18: 917-921.

C. Osborne Hutton and William H. Taft Weddellite in Modern Sediments, Florida Mineralogical Magazine 1965 34 : 256-265.

Tazzoli, V. and C. Domeneghetti (1980) The crystal structures of whewellite and weddellite: re-examination and comparison. American Mineralogist: 65: 327-334.

Van de Vijver, B., R. Vochten, J. Geys, C. Verbruggen, and L. Beyens (1997) Mineralogical observations of weddellite from South Georgia, Subantarctica. Neues Jahrb. Mineral., Monatsh.,
193–202.

Best Localities for Weddellite

Best of Species:Weddellite

Internet Links for Weddellite

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  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Weddellite details from Handbook of Mineralogy (PDF)
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  • Localities for Weddellite

    The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
    (TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
    Antarctica
     
    • Western Antarctica
    Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 1102.
    Australia
     
    • Western Australia
      • Dundas Shire
        • Madura Roadhouse
    Mineralogical Magazine (1977): 41: 33-35.
      • Laverton Shire
        • Lake Rason
    Mineralogical Magazine (1973): 39: 346-348.
      • Moora Shire
    Bridge, P.J., Pryce, M.W., Clarke, R.M., and Costello, M.B. (1978): Sampleite from Jingemia Cave, Western Australia. Mineralogical Magazine 42, 369-371.
    Botswana
     
    • North-West District
      • Ngamiland West District
    Handbook of Mineralogy - Anthony, Bideaux, Bladh, Nichols
    Bulgaria
     
    • Sofiya Oblast (Sofia Oblast)
    J. Mincheva-Stefanova & I. Kostov (1994): Weddellite - a mineral new to Bulgaria. Comptes Rendus de l'Académie Bulgare des Sciences, 47, 69-72.
    Canada
     
    • Nunavut Territory
      • Ellesmere Island
    Gault, C. D. (1986): Weddellite: a new occurrence. Mineralogical Magazine, 50, 738-739.
    • Ontario
      • Haliburton Co.
        • Lutterworth Township
    Mandarino, A. (1983): Weddellite from Lutterworth Township, Haliburton County, Ontario. Canadian Mineralogist, 21, 509-511
    China
     
    • Inner Mongolia Autonomous Region
      • Xilin Gol League (Xilinguole Prefecture)
        • Xilinhot Co. (Xilinhaote Co.)
          • Shengli coal field
    Qi Zhang, Huawen Qi, Ruizhong Hu, Xiaofei Wang (2008): Acta Mineralogica Sinica 28(4), 426-438
    Germany
     
    • Baden-Württemberg
      • Black Forest
        • St Ulrich
    Walenta, K. (2003): Oxalatmineralien aus dem Schwarzwald. Erzgräber 17, 9-16. (in German)
        • Waldshut
          • Detzeln
    Hess, E., Graeser, S. & Gabriel, W. (2011): Das Porphyrwerk Detzeln im Steinatal und seine Mineralien. Lapis 36 (4), 25-35; 54.
        • Wolfach
          • Oberwolfach
            • Frohnbach valley
    K. Walenta: "Die Mineralien des Schwarzwaldes", Weise (Munich), 1992
    Italy
     
    • Emilia-Romagna
      • Modena Province
    Dondi, M. & Puggioli, G. (1990): Minerali organici, 1 parte. Rivista Mineralogica Italiana, 4/1990, 189-206.
    • Liguria
      • La Spezia Province
        • Vara Valley
          • Borghetto Vara
    Del Magro, S., Michelini, A., Giorgi, A. (2000): La weddellite di Cerchiara (La Spezia). Rivista Mineralogica Italianha, 1/2000, 37
    Kolitsch, U., Lackner, E., Ciriotti, M.E. (2008): Lindbergite: primo ritrovamento italiano a Molinello. Addendum-corrigendum. Micro (UK Report), 2/2008, 77-78
      • Lucca Province
        • Massaciuccoli
          • Monte Niquila
    del Magro, S. (2009): Weddellit vom Monte Niquila, Lucca, Italien. Lapis 34 (3), 7.
    • Veneto
      • Venice Province
        • Venice
          • Venice lagoon
    M. Del Monte and C. Sabbioni (1983): Weddellite on limestone in the Venice environment. Environmental Science and Technology, 17, 518-522.
    Russia
     
    • Eastern-Siberian Region
      • Sakha Republic (Saha Republic; Yakutia)
        • Polar Yakutia
          • Bulun District
            • Lena River Basin
    Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
    Pekov, I. (1998) Minerals First discovered on the territory of the former Soviet Union 369p. Ocean Pictures, Moscow
    • Far-Eastern Region
      • Primorskiy Kray
        • Kavalerovo Mining District
          • Dal'negorsk (Dalnegorsk; Tetyukhe; Tjetjuche; Tetjuche)
    Min Rec vol 32, pp 7-30 (2001)
    UK
     
    • England
      • Derbyshire
        • Ashover
          • Milltown
    [MinRec 21:492]
    Rust S.A. (1983): Weddellite - a new British mineral species from Derbyshire. Mineral Realm 3, 22.; Rust, S. Seltene Mineralien aus dem Steinbruch Milltown bei Ashover LAPIS Mineralienmagazin 1994, 12, p.13-17, 58; Ford, T., A. Sarjeant & M. Smith (1993): The minerals of the Peak district of Derbyshire. UK Jour. Mines & Minerals 13, 16-55.
    USA
     
    • Arizona
    Miklancic collection, 13/50
    • Florida
    G. M. Griffin, R. K. Sawyer & S. R. Melkote (1984): Weddellite occurrence in peats and other organic-rich sediments of Florida. Journal of Sedimentary Petrology, 54, 861-868.
    G. M. Griffin, R. K. Sawyer & S. R. Melkote (1984): Weddellite occurrence in peats and other organic-rich sediments of Florida. Journal of Sedimentary Petrology, 54, 861-868.
    • Oregon
      • Sherman Co.
    J. A. Mandarino & N. V. Witt (1983): Weddellite from Biggs, Oregon, U.S.A. Canadian Mineralogist, 21, 503-508.
    • Virginia
      • Amelia Co.
        • Winterham
    Rocks & Minerals 79:4 p 256
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