Jump to: navigation, search


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.

Synonyms and Related Terms

weddelite (sp); calcium oxalate; wedelita (Esp.); weddelite (Port.); Weddelit (Deut.)

Other Properties

Colorless, transparent, tetragonal crytals. Luster = vitreous Streak = white Fracture = conchoidal

Composition Ca(C2O4)-2H2O
Mohs Hardness 4.0
Density 2.02
Molecular Weight 164.13
Refractive Index w=1.523, e=1.544

Additional Information

° 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

Sources Checked for Data in Record