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Weddellite

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Milltown Quarry, Milltown, Ashover, Derbyshire, England, UK
© Steve Rust

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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.

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: Peaks:
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
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[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
[(SO
 
4
)
 
2
|C
 
2
O
 
4
] · 12H
 
2
O
10.AB.70Levinsonite-(Y)
(Y,Nd,La)Al(SO
 
4
)
 
2
(C
 
2
O
 
4
)·12H
 
2
O
10.AB.75Zugshunstite-(Ce)
(Ce,Nd,La)Al(SO
 
4
)
 
2
(C
 
2
O
 
4
)·12H
 
2
O
10.AB.80Novgorodovaite
Ca
 
2
[Cl
 
2
|C
 
2
O
 
4
] · 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[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
German names:
Weddellit
Russian names:
Уэдделлит
Spanish names:
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) rendu 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.

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.

Articles/Blogs about Weddellite

Internet Links for Weddellite

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  • Raman and XRD data at RRUFF project
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    Localities for Weddellite

    Hide Locality List
    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.
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    (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
      • Eucla
        • Madura Motel
    		Mineralogical Magazine (1977): 41: 33-35.
    Mineral. Mag. , G.B. , 1973, 39, pp. 346-348.
    Bulgaria
     
    • Sofiya (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
      • Peterborough Co.
        • Lutterworth Township
    		Mandarino, A. (1983): Weddellite from Lutterworth Township, Haliburton County, Ontario. Canadian Mineralogist, 21, 509-511
    Germany
     
    • Baden-Württemberg
      • Black Forest
        • St Ulrich
    		Walenta, K. (2003): Oxalatmineralien aus dem Schwarzwald. Erzgräber 17, 9-16. (in German)
        • Wolfach
          • Oberwolfach
            • Frohnbach valley
    		K. Walenta: "Die Mineralien des Schwarzwaldes", Weise (Munich), 1992
    Italy
     
    • Liguria
      • La Spezia Province
        • Vara Valley
          • Borghetto Vara
    		Steffen Möckel (pers. commun. to Marco Ciriotti, 2005)
    • 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
      • Saha Republic (Sakha Republic; Yakutia)
        • Polar Yakutia
          • Bulun District
            • Lena River Basin
    • Far-Eastern Region
      • Primorskiy Kray
        • Dal'negorsk (Dalnegorsk)
    		Min Rec vol 32, pp 7-30 (2001)
    UK
     
    • England
      • Derbyshire
        • Ashover
    		[MinRec 21:492]
          • Milltown
    		[Rust, S. Seltene Mineralien aus dem Steinbruch Milltown bei Ashover LAPIS Mineralienmagazin 1994, 12, p.13-17, 58]
    USA
     
    • Arizona
    • 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
    Mineral and/or Locality
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