whewellite


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Related to whewellite: Weddellite

whewellite

[′hyü·ə‚līt]
(mineralogy)
Ca(C2O4)·H2O A colorless or yellowish or brownish, monoclinic mineral consisting of calcium oxalate monohydrate; occurs as crystals.
References in periodicals archive ?
Both whewellite and weddellite have been found in prehistoric open-air rock paintings (Hernanz et al.
All seven samples of dark brown and black rock surface deposits were identified as whewellite, with minor amounts of ankerite, (Ca,Mg,Fe)C[O.sub.3], calcite, and in one case, jarosite, K[Fe.sub.3][(S[O.sub.4]).sub.2][(OH).sub.6] and pyrite Fe[S.sub.2].
Its main forms are the monohydrate (whewellite) and the dihydrate (whedellite) (Gadd 1999, Gorny 2004), unlike those encountered in scanning electron microscopy, where the crystals observed have an irregular morphology with diameters ranging between 50 and 100 um and are insoluble, which affect the nutritional heterogeneity of elements Ca, P, K and Al in the three mortar samples.
1), carbonate and barite veins/veinlets or individual crystals of barite and whewellite are associated with narrow dislocation fractures in the vicinity of major faults.
fuchsina together with this feature it was possible to observe the three strongest diffraction peaks of whewellite, those with d-values of 5.93, 5.79 and 3.65 (JCPDS PDF file 20-0231), respectively.
The major crystalline phase in the 3 biochars produced from eucalyptus feedstocks at 400[degrees]C was whewellite (calcium oxalate, Ca([C.sub.2][O.sub.4]).[H.sub.2]O), and these 3 biochars produced similar diffraction patterns (Fig.
During periods of dune stability the mineralogy was dominated by amorphous silica from diatom shells and sponge spicules and the biogenic calcium oxalate whewellite, (CaC204).
They're all here, in multiple samples ranging in quality from "study grade" to absolutely superb: Freiberg acanthite and stephanite, Schneeberg proustite and erythrite and roselite and uranium-bearing species, Andreasberg pyrargyrite and dyscrasite and fluorite and pink apophyllite, Siegerland malachite and anglesite and millerite and galena, Schwarzwald fluorite and barite and silver, Obermoschel cinnabar and moschellandsbergite, Ems pyromorphite and cerussite, Johanngeorgenstadt mimetite, Ohrenstock hausmannite, Fichtelgebirge topaz and microcline and herderite, Ehrenfriedersdorf cassiterite and fluorapatite, Ilfeld manganite, Ronneburg whewellite, Hagendorf phosphates ...
The components are as follows: ammonium hydrogen urate (AMUR), brushite (BRUS), carbonate apatite (CARB), cystine (CYST), struvite (STRU), uric acid (URIC), weddellite (WEDD), and whewellite (WHEW; Table 1).
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.
We have determined that the rock crust is composed primarily of calcium oxalate in the mineral form whewellite. The origin of the whewellite is unknown.