Weddellite
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Description
A white, glassy mineral composed of Calcium oxalate dihydrate. Weddellite, and Whewellite, are two calcium oxalate minerals which form on the surface of carbonaceous minerals in the presence of microbiological organisms such as lichens. The mineral obtained its name when small crystals of weddellite were found in the sediment of the Weddell Sea near Antartica.
IR-ATR spectrum of Weddelite; Credit: RRUFF
Raman spectrum of Weddelite; Credit: RRUFF
Synonyms and Related Terms
weddelite (sp); calcium oxalate; wedelita (Esp.); weddelite (Port.); Weddelit (Deut.)
Physical and Chemical Properties
- Colorless, transparent, tetragonal crystals.
- Luster = vitreous
- Streak = white
- Fracture = conchoidal
| Composition | Ca(C2O4)-2H2O |
|---|---|
| Mohs Hardness | 4.0 |
| Density | 2.02 g/ml |
| Molecular Weight | 164.13 |
| Refractive Index | w=1.523, e=1.544 |
Resources and Citations
- Mineralogy Database: Weddellite
- M. del Monte, C. Sabbioni, G.Zappia. The origin of calcium oxalates on historical buildings, monuments and natural outcrops. The science of the total environment 67, (1987), pp. 17-39
- B. Ford, I.MacLeod, P.Haydock, "Rock art pigments from Kimberley region of Western Australia: identification of the minerals and conversion mechanisms." Studies in conservation 39, no. 1 (1994), pp. 57-69
- Wikipedia: http://en.wikipedia.org/wiki/Weddellite (Accessed Sept 2, 2005)