Difference between revisions of "Weddellite"
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A white, glassy mineral composed of [[calcium%20oxalate|calcium oxalate]] dihydrate. Weddellite, and [[whewellite|whewellite]], are two calcium oxalate minerals which form on the surface of carbonaceous minerals in the presence of microbiological organisms such as [[lichen|lichens]]. The mineral obtained its name when small crystals of weddellite were found in the sediment of the Weddell Sea near Antartica. | A white, glassy mineral composed of [[calcium%20oxalate|calcium oxalate]] dihydrate. Weddellite, and [[whewellite|whewellite]], are two calcium oxalate minerals which form on the surface of carbonaceous minerals in the presence of microbiological organisms such as [[lichen|lichens]]. The mineral obtained its name when small crystals of weddellite were found in the sediment of the Weddell Sea near Antartica. | ||
| − | + | [[File:Weddelite IR-ATR RRUFF R050242.png|thumb|IR-ATR spectrum of Weddelite; Credit: [https://rruff.info/weddellite/display=default/R050242 RRUFF]]] | |
| + | [[File:Weddelite Raman RRUFF R050242.png|thumb|Raman spectrum of Weddelite; Credit: [https://rruff.info/weddellite/display=default/R050242 RRUFF]]] | ||
== Synonyms and Related Terms == | == Synonyms and Related Terms == | ||
| Line 10: | Line 11: | ||
==Physical and Chemical Properties== | ==Physical and Chemical Properties== | ||
| − | Colorless, transparent, tetragonal | + | * Colorless, transparent, tetragonal crystals. |
| + | * Luster = vitreous | ||
| + | * Streak = white | ||
| + | * Fracture = conchoidal | ||
{| class="wikitable" | {| class="wikitable" | ||
Latest revision as of 12:20, 9 December 2022
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)