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A dihydrate of calcium oxalate; found in renal calculi. Compare: whewellite.
[for Weddell Sea, after James Weddell, Eng. navigator (1787-1834), + -ite]
Farlex Partner Medical Dictionary © Farlex 2012
References in periodicals archive ?
Both whewellite and weddellite have been found in prehistoric open-air rock paintings (Hernanz et al.
Also, in the Sonoran Desert, the weddellite crystals in the dead cacti lying on the ground are converted over 10-20 years into grains of CaC[O.sub.3] (Garvie 2003; Garvie 2006).
By contrast, in vitro studies of fungi abound and, for example, some reveal that wood-rotting fungi can produce extracellular CaOx crystals, of both whewellite and weddellite, and that some of these fungi can dissolve CaOx crystals (Guggiari et al.
(1983) found that 20% of Ca in the forest floor litter of a 40-year-old karri forest in Western Australia was present as weddellite (Ca[C.sub.2][O.sub.4].2[H.sub.2]O).
Weddellite was found in sandstone country along the walls and ceiling of a shelter in the Mitchell Plateau (Figure 3).
On the formation of weddellite in Chamaecereus silvestrii, a cactaceae from northern Argentina.
Small, cloudy crystals of weddellite have been identified in a pocket with whewellite at the Nikolaevskiy mine (Ponomarenko, personal communication, 2000).
The key locations are within tropical Australia where rocks have been found covered with skins of various compositions, some of them with very complex chemistry, including the presence of oxalate salts, for example the minerals whewellite (Ca[C.sub.2][multiplied by][O.sub.4].[H.sub.2]O) and weddellite (Ca[C.sub.2][O.sub.4][multiplied by]2[H.sub.2]O), with carbon atoms having been derived from atmospheric [CO.sub.2] via complex pathways thought to include biological fixation (probably by bacteria or algae).
More specifically, there was no difference between the two groups of patients concerning weddellite (calcium oxalate dihydrate) crystalluria, however, a highly significant difference (p < [10.sup.-8]) was found for whewellite (calcium oxalate monohydrate) crystalluria.
Further examination revealed that whewellite was much more common than weddellite: 63% of crystalluria involving calcium oxalate was pure whewellite and in the remaining 37%, whewellite was the major component.
Weddellite, the polyhydrate form of calcium oxalate, was not evident in any of the samples.