Weddellite

Weddellite (CaC2O4·2H2O) is a mineral form of calcium oxalate named for occurrences of millimeter-sized crystals found in bottom sediments of the Weddell Sea, off Antarctica. Occasionally, weddellite partially dehydrates to whewellite, forming excellent pseudomorphs of grainy whewellite after weddellite's short tetragonal dipyramids.
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Weddellite a form of calcium oxalate. Found in oxalate uroliths. [more]Weddellite - Community and Resources

General Information:
 Chemical Formula:
Ca(C2O4)·2(H2O)
 Composition:
(Molecular Weight = 164.13 gm)
Calcium 24.42 % Ca
Hydrogen 2.46 % H 
Carbon 14.64 % C 
Oxygen 58.49 % O 
 Empirical Formula:
Ca(C2O4)·2(H2O)
Physical Properties:
 Cleavage:
[010] Good
 Color:
colorless, tan, white, yellowish brown, or brown.
 Density:
2.02
 Diaphaniety:
Transparent
 Hardness:
4 - Fluorite
 Luster:
Vitreous (Glassy)
 Streak:
white
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