Weddellite Mineral Data

Weddellite Mineral Data +

[Content and History] [Recent Issues] [Back Issues] [Subscriptions] [Contacts]
See Also: [Diamond Crystals] [Excalibur Minerals] [Hudson Institute] [Minerals on CDROM]
Mineral News was founded some twenty years ago and has developed a following of
avid mineral collectors seeking timely information about new finds and other items
of interest to the collector community. Articles are solicited from collector and scientific authors.

General Weddellite Information

Chemical Formula:

Ca(C2O4)·2(H2O)

Composition:

Molecular Weight = 164.13 gm

Calcium 24.42 % Ca 34.17 % CaO

Hydrogen 2.46 % H 21.95 % H₂O

Carbon 14.64 % C 43.88 % C₂O₃

Oxygen 58.49 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca(C₂O₄)·2(H₂O)

IMA Status:

Valid Species (Pre-IMA) 1942

Locality:

Link to MinDat.org Location Data.

Name Origin:

Named for the Weddel sea, Antactica.

Synonym:

Calcium Oxalate

ICSD 30783

PDF 17-541

Weddellite Image

Images:

Weddellite

Comments: Tan prismatic weddellite crystal sprays in vug.
Location: Near Biggs, Wasco County, Oregon, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Weddellite Crystallography

Axial Ratios:

a:c = 1:0.59635

Cell Dimensions:

a = 12.33, c = 7.353, Z = 8; V = 1,117.87 Den(Calc)= 1.95

Crystal System:

Tetragonal - DipyramidalH-M Symbol (4/m) Space Group: I 4/m

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 6.18(1), 2.775(0.65), 4.42(0.3),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

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

Physical Properties of Weddellite

Cleavage:

[010] Good

Color:

Colorless, Tan, White, Yellowish brown, Brown.

Density:

2.02

Diaphaniety:

Transparent

Hardness:

4 - Fluorite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Weddellite

Gladstone-Dale:

CI meas= -0.804 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.869 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2736,KPDmeas= 0.2641,KC= 0.1464

Optical Data:

Uniaxial (+), w=1.523, e=1.544, bire=0.0210.

Calculated Properties of Weddellite

Electron Density:

r_electron=2.07 gm/cc
note: r_Weddellite=2.02 gm/cc.

Fermion Index

Fermion Index = 0.00222
Boson Index = 0.99778

Photoelectric:

PE_Weddellite= 3.15 barns/electron
U=PE_Weddellite x r_electron= 6.51 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Weddellite is Not Radioactive

Weddellite Classification

Dana Class:

50.1.2.1 (50)Salts of Organic Acids

(50.1)(Oxalates)

(50.1.2)Dana Group

50.1.2.1 Weddellite Ca(C2O4)·2(H2O) I 4/m 4/m

50.1.2.2 Caoxite! Ca(C2O4)·3(H2O) P1 1

Strunz Class:

IX/A.01-20 IX - Organic compunds

IX/A - Oxalates. Salts from organic acids. [C2O4]2- arranged after increasing cation size

IX/A.01 - Whewellite - Wheatleyite series

IX/A.01-05 Natroxalate! Na2C2O4 P 2₁/a 2/m

IX/A.01-10 Whewellite Ca(C2O4)·(H2O) P 2₁/n 2/m

IX/A.01-20 Weddellite Ca(C2O4)·2(H2O) I 4/m 4/m

IX/A.01-25 Caoxite! Ca(C2O4)·3(H2O) P1 1

IX/A.01-28 Novgorodovaite! Ca2(C2O4)Cl2·2(H2O) I2/m 2/m

IX/A.01-30 Oxammite (NH4)2(C2O4)·(H2O) P 2₁2₁2 2 2 2

IX/A.01-40 Glushinskite Mg(C2O4)·2(H2O) C 2/c 2/m

IX/A.01-50 Humboldtine Fe(C2O4)·2(H2O) I2/a 2/m

IX/A.01-55 Lindbergite! Mn(C2O4)·2(H2O) C 2/c 2/m

IX/A.01-60 Minguzzite K3Fe(C2O4)3·3(H2O) P 2₁/c 2/m

IX/A.01-70 Zhemchuzhnikovite NaMg(Al,Fe)(C2O4)3·8(H2O) Unk Trig

IX/A.01-80 Stepanovite NaMgFe(C2O4)3·8-9(H2O) Unk Trig

IX/A.01-90 Moolooite Cu(C2O4)·n(H2O)(n<1) Unk Ortho

IX/A.01-100 Wheatleyite Na2Cu(C2O4)2·2(H2O) P1 1

IX/A.01-110 Coskrenite-(Ce)! (Ce,Nd,La)2(SO4)2(C2O4)·8(H2O) C 2/c 2/m

IX/A.01-120 Levinsonite-(Y)! (Y,Nd,La)Al(SO4)2(C2O4)·12(H2O) P 2/n 2/m

IX/A.01-130 Zugshunstite-(Ce)! (Ce,Nd,La)Al(SO4)2(C2O4)·8(H2O) C 2/c 2/m

Other Weddellite Information

References:

NAME( Athena) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Weddellite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (MinSocAm)
8 - Handbook of Mineralogy (UofA)
9 - MinDAT
10 - MinMax(Deutsch)
11 - MinMax(English)
12 - Mineralienatlas (Deutsch)
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST

Search for Weddellite using:

[ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Weddellite :

AA Mineral Specimens

B & L Fine Minerals

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

MineralsWeb Fine Minerals

The GeoZone

Wrights Rock Shop

Translate Weddellite Mineral Data :

Ask about Weddellite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Weddellite Specimen Label here :

Weddellite

Ca(C2O4)·2(H2O)
Dana No: 50.1.2.1 Strunz No: IX/A.01-20
Locality:

Notes: