DOCSLIB.ORG

503.Pdf by Guest on 30 September 2021 504 the CANADIAN MINERALOGIST

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
503.Pdf by Guest on 30 September 2021 504 the CANADIAN MINERALOGIST Canadian Mineralogist Vol. 2l; pp. 503-508(1983) WEDDELLITE FROM BIGGS, OREGON, U.S.A. J. A. MANDARINO Depdrtmentof Mineralogltand Geology,Royal Ontario Museum,100 Queen's Park, Toronto, Anturio M5S 2C6 and Department of Geologl, University of Toronto, Toronto, Ontario MSS lAl NOBLE V. WITT I319 N.E. IITth Street, Vancouver,Washington 98665, U.S.A. ABSTRACT coeur r6sineux brun fonc€ renfermant un matdriau organique ind€termin6. Le matdriau brun pdle possddeune The rare mineral weddellite, CaCrOo.(2+x)H2O, has duretdd'environ 4 et une densit€de2.02Q), La weddellite beenidentified from an occurrencenear Biggs, Oregon, est tetra&onale,de grpupe spatial I4/m, o 12,33(2),c U.S.A. Crystal$up to 5 x 5 x 40 mm occur in cavities 7.353(3)A, V 1117.9et, z = 8. L'analysechimique du in nodulesof the so-called"Biggs jasper". The nodules materiau blanc donne CaO 35.4, CzO343,2, }J2O 24.7, are in lake-bottom sedimentssandwiched between basalt somme 103.3%oen poids. La formule empiriqueobtenue flows of Mioceneage. Associated minerals are quartz and d partir de cesdonn€es est Ca1.04C1.97O0.6,2.26H2Oott, whewellite (CaC2O4.H2O).The whewellite appears to id6alement, CaC2Oa.2.26HtO;la densite calcul€e est replacesome of the weddellite.The weddelliteoccurs as 2.020(4).Le mat6riaublanc est optiquementuniaxe ( + ), tan, euhedral crystals and as white, fibrous aggregates d'indices principaux ot 1,524 et e 1.5U. L'indice de surroundingsome of the euhedralcrystals. The euhedral compatibilit6,0.008, indique une compatibilitt supdieure crystalsAre dull to vitreousin lustre and often havea dark de la ddnsitdavec donn6esoptiques et chimiques. brown, resinouscore containingan undeterminedorganic (Traduit par la R6daction) material; the white material has a silky lustre. The hardness is about 4 and the density is 2.02(2) g/cm3 for the tan Mots-cl6s:weddelllte, Or6gon, oxalate, calcium, whewellite. outer sheUof the euhedralcrystals. Weddet-fite is tetragoqal, spacegroup I4/m, a 12.33(2),c 7.353(3)A, V ttfi.g N, Z -- 8. Analysis of the white material gave CaO 35.4, INTRODUCTIoN C2O343.2, H2O 24.7, total 103.3wt. 90. The empirical formula derived from these data is Ca1.64C1.97Oa.so. Although the substance now called weddellitehas 2.26H2O or, ideally, CaC2Oa.2.26HrO;the calculated been known for many years, its natural occurrence densityis 2.020\4)g,/cm:. Optically, the white material is was restricted to plants and animals. There has been = = uniaxial (+), with u 1.524 and e 1.544. The much confusion in the literature as to the chemical compatibility index is 0.008, indicating superior composition of the compound. For many ye€[s, it compatibility of the density, optical and chemicaldata. was considered to be calcium oxalate trihydrate, Keywords: weddellite, Oregon, oxalate, calcium, whewel- CaCrOo.3HrO. It was not until Bannister & Hey lite. (1936) identified the compound from the Weddell Sea, near Antarctica, that many of the mysteries Sounaatnr surrounding this material were solved. The material that Bannister "& Hey described was found as Le min6ral rare weddellite, CaC2Oa.(2+iH2O, a 6td transparent, colorless, tetragonal bipyramidal identifi6 dans un gite prds de Biggs, en Ordgon, E-U. Il crystals in bottom sediments from the central part sepresente en cristauxpouvant atteindre5 X 5 x 40 mm of the Weddell Sea. The samples in which they occur dans descavit6s de nodulesdu soi-disant'Jaspe de Biggs". were dredged from depths between 4434 and 5008 Les nodules se trouvent dans des s&iments Iacustres metres. The extremely sharp crystals range in size intercaldsentre des coul6es basaltiques d'6ge miocine. Les from 0.2 x 0.1 to 0.3 x 0.15 mm. They are uniaxial mindraux associ6s sont le quartz et la whewellite ( + with a : 1.523 and a birefringence of about CaC2Oa.H2O,La whewellitesemble remplacer une partie ), de la weddellite.Celle-ci se pr€sente en cristauxidiomorphes 0.02. The density could not be measured because of brun p6le et en agregatsfibreux blancsentourant certains the small size of the crystals. A single-crystal X-ray cristaux idiomorphes.Les fibres ont un 6clat soyeux;les study showed that theyoare tetragonal, space group cristaux ont rin 6clat mat i vitreux et montrent souvent un I4/m, a 12.40, c 7.37 A, c:a : 0.594:,1.The only 503 Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/21/3/503/3419971/503.pdf by guest on 30 September 2021 504 THE CANADIAN MINERALOGIST form noted is the tetragonal bipyramid {0ll}. preservedin a 7090alcohol solution, were somesmall Although there was not sufficient material for a tetragonalbipyramids that are uniaxial ( + ), with c.r completechemical analysis, Bannister & Hey found = 1.5237and e : 1.5434.They gave an X-ray. that the mineral gave an X-ray powder-diffraction powder-diffraction pattern identical to that of pattern identical to that of some of the calcium weddellite.Thus, the original authigenicnature of oxalate crystalspresent in human renal calculi. A the Weddell Sea crystals was confirmed. Further study of the latter crystalsgave more completedata confirmation is given by Marlowe (1970), who concerningthe compound. Its hardnessis about 4, identified weddellitein bottom sedimentsfrom the and the crystalsare uniaxial(+), ,o 1.523,e 1,544. St. Lawrenceand Saguenayrivers in Quebec.His The measureddensity is 1.99g,/cm3; after a correc- samples were preserved in alcohol, so that the ,,dahlite', tion introduced to account for 4Vo weddellite could not have formed through the (carbonate-hydroxylapatite),the true densityis found decompositionof organic material in the samples. to be 1.94 g/cm3, Two chemical analyseswere It is interesting to note that the original Weddell Sea carried out and gavepractically the sameresults, and sampleswere preservedin alcohol at the time that the formula was established as CaC2O4.2H2O. they were collected. Unfortunately, during the BecauseBannister & Hey felt that there was still some 30-yearstorage before they were studiedby Bannister doubt about the water content in the Weddell Sea & Hey (1936), some of the sampleshad dried up crystals,they decidednot to namethe mineral. The becauseof defectivecorks. It is not known whether sharpnessof the crystalsand the absenceof any signs the samplesin which weddellitecrystals were found of abrasion indicated that they are authigenic. werestill preservedin alcohol or weresome of those In a discussionof the composition of human that had lost the fluid. urinary calculi, in particular those made up of In addition to its occurrence plants ' in animals and carbonate-hydroxylapatite and hydroxylapatite, and in bottom sediments,weddellite has been re- Frondel & Prien (1942)used the name weddellite for ported from older rocks. Slovenec& Sinkovec(1973, the first time for CaC2Oa.2H2O,but gaveno data. 1974) identified very fine-grained whewellite and Prien & Frondel (1947)noted that the compound was weddelliteamong the insolubleresidues of an Upper very abundantin human urinary calculi. The material Cretaceouslimestone in Yugoslavia.Weddellite and also is producedpathologically by other mammals, whewellite have beenfound on Cretaceousophiolitic such as the hippopotamus,as cited by Bannisterer rocks in Italy by Tirelli (1977).Mandarino (1983) ol. (1947),and dogs, as noted by Milton & Axelrod noted the presenceof weddellite on calcium-rich (1951).The first nonpathologicaloccurrence of the rocks of Precambrian age in Ontario. The compound in'an animal was repofied by Lowenstam occurrences noted by both Tirelli (1977) and (1968), who found that the glzzard plates of the Mandarino (1983)probably are related to oxali6 acid deepwater gastropod, Scaphander cylindrellus, produced by lichens. Decaying vegetable fibres consist of weddellite. Traill (1970) reporred probably are the cause of the weddellite and weddellite as colorless crystals in spongespicules whewellitepresent in a Chinesewall painting at the from Fisher Strait, Hudson Bay area, N.W.T. Royal Ontario Museum(pers. comm., the Canadian The compound is common in someplants and was Conservation Inslitute, National Museums of observedin the common onion, Allium cepa, by Canada). Honneger (1952). Knobloch & Kalina (1968) In September197 9, a specimenof an unidentified identified the compound in the plant Spyrogyra. The mineral from Biggs,Oregon, U.S.A., wassubmitted extensiveassociation of weddelliteand other oxalates for identification to the seniorauthor by the junior with lichens and fungi is summarizedby Mandarino author. An X-ray powder-diffractionpattern of the (1983). mineral proved to be the sameas that of weddellite. A second occurrence of weddellite in Becausethe weddellite in all the previously described ocean-bottomsediments was described by Hutton & occurrencesis very fine-grained, with crystals rarely Taft (1965). Their sampleswere dredged from a reaching an overall size of 1/+firtr., the specimens depth of about one fathom (about 2 metres)off the from Oregon provided an opportunity to describe southwesterncoast of Florida. Hutton & Taft cast what are now the largest crystals of weddellite doubt on the authigenicnature of their material as known. well as that from the Weddell Seabecause they felt . that the oxalate could have formed in both setsof APPEARANCE AND PHYSICAL PROPERTIES samplesduring the long period of storagebetween the datesof collectionand examination.During his The Biggs weddellite ocqurs as large, euhedral study of the deepwatergastropod mentioned earlier, crystals (up to 5 x 5 x 40 mm) in cavities in the Lowenstam(1968) also examineda sanple of bottom so-called"Biggs jasper". The euhedralcrystals are sedimentdredged from a depth of 4196metres in the tan and have a dull to vitreous lustre. They Weddell Sea. In this sample, which had been comrqonly have a {ark brown, resinous core that Downloaded from http://pubs.geoscienceworld.org/canmin/article-pdf/21/3/503/3419971/503.pdf by guest on 30 September 2021 WEDDELLITE FROM BIGGS. OREGON. U.S.A. 505 contains an unidentified organic material. Someof and show the forms {010}, {011} and {001}. The the euhedral crystals are coated with a secondary prismatic nature of the Biggs material (Figs.
Load more

Recommended publications
  • DESCRIPTIVE HUMAN PATHOLOGICAL MINERALOGY 1179 but Still Occursregularly
    Amerkan Mincraloght, Volume 59, pages I177-1182, 1974 DescriptiveHuman Pathological Mineralogy Rrcneno I. Gmsox P.O. Box I O79, Dauis,C alilornia 95 6 I 6 Absfract Crystallographic, petrographic, and X-ray powder difiraction analysis of approximately 15,000 samples showed that the most common mineral constituents of human pathological concretions are calcium oxalates (whewellite and weddellite), calcium phosphates (apatite, brushite, and whitlockite), and magnesium phosphates (struvite and newberyite). Less are monetite, hannayite, calcite, aragonite, vaterite, halite, gypsum, and hexahydrite."o-rnon of the variables determining which minerals precipitate, the effects of different pH values on deposi- tional conditions are most apparent, and are shown by occurrences and relationships among many of the minerals studied. A pH-sensitive series has been identified among magnesium phosphatesin concretions. Introduction The study was carried out over a period of three The importanceof mineralogyin the field of medi- years.Composition was confirmedby X-ray powder cine lies in the applicationof mineralogicalmethods diffraction and polarizing microscopy;sequence was to study pathologicalmineral depositsin the human arrived at from considerationsof microscopic tex- body. Urology benefitsgreatly becauseconcretions tural and crystallographicrelationships. More than of mineral matter (calculi) are common in the 14,500samples were derivedfrom the urinary sys- urinary system.The value of mineralogicalanalysis tem of kidneys,ureters, bladder, and urethra; the of urinary material was first describedby prien and remaining samples are not statistically significant Frondel (1947). Mineralogistsmay be unawareof and arediscussed only briefly. the variability and nature of such compounds be- Calcium cause reports are usually published in medical Oxalates journals. This investigationreports the mineralogy Whewellite, CaCzOE.H2O,and weddellite, CaCz- and possiblepathological significanceof these min- O4'2H2O,are very uncommonin the mineralworld.
    [Show full text]
  • The Importance of Minerals in Coal As the Hosts of Chemical Elements: a Review
    The importance of minerals in coal as the hosts of chemical elements: A review Robert B. Finkelmana,b, Shifeng Daia,c,*, David Frenchd a State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, China b University of Texas at Dallas, Richardson, TX 75080, USA c College of Geoscience and Survey Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China d PANGEA Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia *, Corresponding author: [email protected]; [email protected] Abstract Coal is a complex geologic material composed mainly of organic matter and mineral matter, the latter including minerals, poorly crystalline mineraloids, and elements associated with non- mineral inorganics. Among mineral matter, minerals play the most significant role in affecting the utilization of coal, although, in low rank coals, the non-mineral elements may also be significant. Minerals in coal are often regarded as a nuisance being responsible for most of the problems arising during coal utilization, but the minerals are also seen as a potentially valuable source of critical metals and may also, in some cases, have a beneficial effect in coal gasification and liquefaction. With a few exceptions, minerals are the major hosts of the vast majority of elements present in coal. In this review paper, we list more than 200 minerals that have been identified in coal and its low temperature ash, although the validity of some of these minerals has not been confirmed. Base on chemical compositions, minerals found in coal can be classified into silicate, sulfide and selenide, phosphate, carbonate, sulfate, oxide and hydroxide, and others.
    [Show full text]
  • Lite Geology 36: New Mexico's Coal and Electricity Industries
    Lite fall 2014 New Mexico’s Coal and Electricity issue 36 Industries Escalante Generating Station. Photo courtesy of Tri-State Generating and Transmission Association. In This Issue... New Mexico’s Coal and Electricity Industries and the Clean Air Act Caron Dioxide Emissions: New Guidelines and Economic Challenges Global Impacts of Coal Production • Replacement Fuels for Coal-Fired Electricity Water Use at Coal-Fired Power Plants Earth Briefs • Crossword Puzzle New Mexico’s Most Wanted Minerals—Whewellite New Mexico’s Enchanting Geology Classroom Activity: Cupcake Core Sampling Through the Hand Lens • Short Items of Interest NEW MEXICO BUREAU OF GEOLOGY & MINERAL RESOURCES A DIVISION OF NEW MEXICO TECH http://geoinfo.nmt.edu/publications/periodicals/litegeology/current.html NEW MEXICO’S COAL AND ELECTRICITY INDUSTRIES AND THE CLEAN AIR ACT Gretchen Hoffman Editor’s Note: This issue of Lite Geology is the second in a series of totaled $121.9 million. Along with the economic impact of three issues, all related to new technologies in the energy industries. coal mining in the state, 68% of the total electricity generated The last issue addressed new technologies in the oil and gas industry, in New Mexico comes from coal combustion. Approximately this issue focuses on coal and coal-fired electrical generation industries, and the third will address the renewable energy sector. one-third of this electricity is consumed in other states. In New Mexico, 34% of the total energy consumed comes from coal. Coal in New Mexico Generating Stations Using New Coal has played a significant role in New Mexico’s history. Coal was used by the early forts and settlements, the rail- Mexico Coal roads, and the smelters built in the territory after the Civil New Mexico’s three major coal-fired power generating sta- War.
    [Show full text]
  • Origin of the Whewellite-Rich Rock Crust in the Lower Pecos Region of Southwest Texas and Its Significance to Paleoclimate Reconstructions
    Origin of the Whewellite-Rich Rock Crust in the Lower Pecos Region of Southwest Texas and its Significance to Paleoclimate Reconstructions JON RUSS Department of Chemistry, Newberry College, Newberry, South Carolina 29108 RUSSELL L. PALMA Department of Physics, Sam Houston State University, Huntsville, Texas 77341 DAVID H. LOYD Department of Physics, Angelo State University, San Angelo, Texas 76909 THOMAS W. BOUTTON Department of Rangeland Ecology and Management, Texas A&M University, College Station, Texas 77843 AND MICHAEL A. COY Electron Microscopy Center, Texas A&M University, College Station, Texas 77843 Received February 2I, 1996 A calcium oxalate (whewellite)-rich crust occurs on exposed limestone surfaces in dry rock and open air shelters in the Lower Pecos region of southwest Texas. The crust, which also contains gypsum and clay, formed over silica-rich limestone during the Holocene. SEM and optical photomicrographs reveal similarities between whewellite microstructures and the lichen Aspicilia calcarea. This desert lichen is known to produce calcium oxalate, and has been found in several sites in the region. The ubiquity of the whewellite-rich crust in the Lower Pecos shelters suggests that the lichen flourished in the past. Since A. calcarea is a desert species, the virulence of the organism likely peaked during xeric climate episodes then waned during mesic periods. Thus, radiocarbon ages of whewellite would correspond to dry climate periods experienced in the region, while periods with few or no 14C data would indicate wet climate episodes. A preliminary paleoclimate reconstruction based on fourteen AMS 14C dates indicates the Lower Pecos experienced dry to wet climate fluctuations during the late Holocene.
    [Show full text]
  • A Calcium Oxalate Phase Stability and Dissolution Study
    A CALCIUM OXALATE PHASE STABILITY AND DISSOLUTION STUDY By NAUF SALEH Al-JUHANI A thesis submitted to the Graduate School-Camden Rutgers, The State University of New Jersey In partial fulfillment of the requirements For the degree of Master of Science Graduate Program in Chemistry Written under the direction of Dr. George Kumi and approved by ________________________ Dr. George Kumi ________________________ Dr. Georgia Arbuckle-Keil ________________________ Dr. Hao Zhu Camden, New Jersey May 2017 THESIS ABSTRACT A calcium oxalate phase stability and dissolution study By NAUF SALEH Al-JUHANI Thesis Director: Dr. George Kumi The presence of calcium oxalate (CaOx) hydrate crystals, which have low solubility in water, is widespread in nature. These crystals cause undesirable effects in certain aspects of human life, and many of these problems are still unsolved due to the lack of necessary information about the crystallization and dissolution mechanisms of these crystals. To obtain more insight into the thermal stability of CaOx crystals, a comparative study of calcium oxalate monohydrate (COM) dendritic and calcium oxalate dihydrate (COD) bipyramidal crystals has been undertaken using a combination of Raman microscopy and thermal stage. Crystal structure transformations in these crystals with respect to various temperatures were determined. Experimental results indicate that COM is stable up to ~110 °C, and above this temperature the anhydrous calcium oxalate (COA) forms. This transformation is reversible since the COA crystals created convert back to the COM phase upon cooling to temperatures below this transition temperature. In contrast, the COD phase is stable up to ~120 °C, and above this temperature COD dehydrates and transforms to COA.
    [Show full text]
  • New Mineral Names*
    American Mineralogist, Volume 59, pages 873-475, 1974 NEWMINERAL NAMES* Mrcnapl Frprscnpn Bjarebyite* Borovskite* P. B. MooRE, D. H. LuNo, eNo K, L. KBrsrBn (1923) A. A. Yerovor, A. F. Sroonov, N. S. RuomnEvsKrr AND Bjarebyite, (Ba,Sr)(Mn,Fe,Mg),AL(Olt)s(por)a a new I. A. Buo'ro (1973) Borovskite, PdSbTer, ? n€w mineral. species. Mineral. Rec. 4, 282-285, Zapiski Vses.Mineral. Obshch. 102, 427431 (in Russian). Microprobe pure Microprobe analysis by G. Z. Zecttnan gave (av. 60 area analyses, using metals and BirTer as standards, on 4 grains gave scan) Ba 21.81, Sr O.79, Ca 0.06, Mn 7.15, Fe 6.95, Pd 32.94, 31.90, 32.37, 32.37, av. 32.39; Pt. 1.21, 1.25, 1.23, Mg 0.84, Al 7.01, giving the formula above with pOr and 1.20, av. 1.23; Ni 0.26, O.24,0.26, O.25,av.0.25; Fe OH on the basis of the structure. The ratio Mn/Fe is 0.04, 0.04, 0.06, 0.02, av. 0.04; Sb 1,0.92,10.97, 11.01, 11.00, av. 10.98; variable, indicating the likelihood of the occurrence of an Bi 3.35,3.34,3.34, Fe'g*analogue. av. 3.34; Te 51.86, 52.39, 51.70, 51.93, av. 51.97; sum 100.58, 99.98, percent, Weissenberg and rotation photographs show the mineral 10O.14, 100.11, av. 10O.21 corre- sponding to (Pd" (Sbo to be monoclinic, space grotp P2r/m, a 8.930, b lZ.O73, 6PtowNio orFeo o.) *Bio ru)Te" or, or PdaSbTe+.
    [Show full text]
  • Calcium Oxalate Crystal Types in Three Oak Species (Quercus L.) in Turkey
    Turk J Biol 36 (2012) 386-393 © TÜBİTAK doi:10.3906/biy-1109-35 Calcium oxalate crystal types in three oak species (Quercus L.) in Turkey Bedri SERDAR1, Hatice DEMİRAY2 1Karadeniz Technical University, Faculty of Forestry, Department of Forest Botany, Trabzon - TURKEY 2Ege University, Faculty of Science, Department of Botany, İzmir - TURKEY Received: 30.09.2011 ● Accepted: 17.02.2012 Abstract: Crystal types from 3 oak species representing 3 diff erent sections of the genus Quercus were identifi ed. Crystals were studied with scanning electron microscopy aft er localisation by light microscopy. Th e crystals were composed of calcium oxalate silicates as whewellite (calcium oxalate monohydrate) composites. In Quercus macranthera Fisch. et Mey. subsp. syspirensis (C.Koch) Menitsky (İspir oak) from the white oaks (section Quercus: Leucobalanus), whewellite and trihydrated weddellites coexisted. Axial parenchyma cells included 30 crystal chains with walls as chambers in uniseriate ray cells; some cells had many crystals without any chambers and were small. Long thin crystals were found adherent to the membrane in the tracheary cell lumens of latewood. Quercus cerris L. var. cerris (hairy oak/Turkey oak) from the red oak group (section Cerris Loudon) is extremely rich in rhomboidal crystals. In species Quercus aucheri Jaub. et Spach (grey pırnal) from the evergreen oak group (section Ilex Loudon) rhomboidal crystals were found in axial parenchyma and multiseriate ray cells. Lignifi ed wall layers were not observed around the crystals with chambers. Key words: Calcium oxalate silicate, crystals, crystal morphology, Quercus, Turkey Introduction some Araceae (e.g., Xanthosoma sagittifolium) (2). Most plants invest considerable resources in In monocotyledons 3 main types of calcium oxalate cytoplasmic inclusions such as starch, tannins, crystal occur: raphides, styloids, and druses.
    [Show full text]
  • Origin of the Whewellite-Rich Rock Crust in the Lower Pecos Region of Southwest Texas and Its Significance to Paleoclimate Reconstructions
    QUATERNARY RESEARCH 46, 27±36 (1996) ARTICLE NO. 0041 Origin of the Whewellite-Rich Rock Crust in the Lower Pecos Region of Southwest Texas and Its Signi®cance to Paleoclimate Reconstructions JON RUSS Department of Chemistry, Newberry College, Newberry, South Carolina 29108 RUSSELL L. PALMA Department of Physics, Sam Houston State University, Huntsville, Texas 77341 DAVID H. LOYD Department of Physics, Angelo State University, San Angelo, Texas 76909 THOMAS W. BOUTTON Department of Rangeland Ecology and Management, Texas A&M University, College Station, Texas 77843 AND MICHAEL A. COY Electron Microscopy Center, Texas A&M University, College Station, Texas 77843 Received February 21, 1996 generally considered rare in geological environments A calcium oxalate (whewellite)-rich crust occurs on exposed (Graustein et al., 1977; ZÏaÂk and SkaÂla, 1993), but are now limestone surfaces in dry rock and open air shelters in the Lower known to be common components in natural rock accretions Pecos region of southwest Texas. The crust, which also contains (Del Monte and Sabbioni, 1987; Del Monte et al., 1987; Watch- gypsum and clay, formed over silica-rich limestone during the man, 1990, 1991; Edwards et al., 1991; Scott and Hyder 1993; Holocene. SEM and optical photomicrographs reveal similarities Chaffee et al., 1994; Watchman et al., 1995). Evidence indi- between whewellite microstructures and the lichen Aspicilia calc- area. This desert lichen is known to produce calcium oxalate, and cates that some oxalate-rich crusts are produced by lichens (Del has been found in several sites in the region. The ubiquity of the Monte and Sabbioni, 1987; Del Monte et al., 1987; Russ et al., whewellite-rich crust in the Lower Pecos shelters suggests that the 1995), although other biological and nonbiological mechanisms lichen ¯ourished in the past.
    [Show full text]
  • Structural Crystal Chemistry of Organic Minerals: the Synthetic Route
    STRUCTURAL CRYSTAL CHEMISTRY OF ORGANIC MINERALS: THE SYNTHETIC ROUTE (1) Oscar E. Piro (1) Departamento de Física, Facultad de Ciencias Exactas, Universidad Nacional de La Plata e Instituto IFLP (CONICET, CCT-La Plata), C. C. 67, 1900 La Plata, Argentina Correo Electrónico: [email protected] ‘Organic minerals’ means naturally occurring crystalline organic compounds including metal salts of formic, acetic, citric, mellitic and oxalic acids. The primary tool to disclose their crystal structure and their mutual relationship with each other and with synthetic analogues and also to understand their physicochemical properties is X-ray diffraction. The structure of several synthetic organic minerals was solved well before the discovery of their natural counterpart. On the other hand, complete crystal structure determination of early discovered organic minerals had to await the advent of combined synthetic and advanced X-ray diffraction methods. We review here the crystallography of organic minerals showing the importance of structural studies on their synthetic analogues. This will be highlighted by the cases of synthetic novgorodovaite, Ca 2(C 2O4)Cl 2·2H 2O, and its heptahydrate analogue, Ca 2(C 2O4)Cl 2·7H 2O, and the isotypic to each other stepanovite, NaMg[Fe(C 2O4)3]·9H 2O, and zhemchuzhnikovite, NaMg[Al xFe 1-x(C 2O4)3]·9H 2O. 1. Introduction Full crystallographic characterization of minerals by structural X-ray diffraction methods is frequently hampered by several drawbacks, including unavailability of natural samples, lack of purity and other disorders of these materials, and the difficulty in finding natural single crystals suitable for detailed structural work.
    [Show full text]
  • Oxalate Formation Under the Hyperarid Conditions of the Atacama Desert As a Mineral Marker to Provide Clues to the Source Of
    PUBLICATIONS Journal of Geophysical Research: Biogeosciences RESEARCH ARTICLE Oxalate formation under the hyperarid conditions 10.1002/2016JG003439 of the Atacama desert as a mineral marker Key Points: to provide clues to the source • Oxalate minerals were found in the hyperarid conditions of the Salar of organic carbon on Mars Grande basin, Atacama desert • Biological versus abiotic pathways Z. Y. Cheng1, D. C. Fernández-Remolar2, M. R. M. Izawa3,4,5, D. M. Applin4, M. Chong Díaz6, were recognized using mineral and 7 7 1 1,8 7 geochemical techniques M. T. Fernandez-Sampedro , M. García-Villadangos , T. Huang , L. Xiao , and V. Parro • Such information can be used to 1 2 reveal the origin of organic carbon Planetary Science Institute, School of Earth Sciences, China University of Geosciences, Wuhan, China, Environmental 3 on Mars Science Centre, British Geological Survey, Keyworth, UK, Department of Earth Sciences, Brock University, St. Catharines, Ontario, Canada, 4Hyperspectral Optical Sensing for Extraterrestrial Reconnaissance Laboratory, Department of Geography, University of Winnipeg, Winnipeg, Manitoba, Canada, 5Planetary Science Institute, Tucson, Arizona, USA, 6Department of Supporting Information: 7 • Supporting Information S1 Geological Sciences, Universidad Católica del Norte, Antofagasta, Chile, Centro de Astrobiologia (INTA-CSIC), Torrejon de Ardoz, Spain, 8Space Science Institute, Macau University of Science and Technology, Macau, China Correspondence to: D. C. Fernández-Remolar, [email protected] Abstract In this study, we report the detection and characterization of the organic minerals weddellite (CaC2O4 ·2H2O) and whewellite (CaC2O4 ·H2O) in the hyperarid, Mars-like conditions of the Salar Grande, Citation: Atacama desert, Chile. Weddellite and whewellite are commonly of biological origin on Earth and have great Cheng, Z.
    [Show full text]
  • Phase Transitions of Calcium Oxalate Trihydrate and Epitaxy in the Weddellite-Whewellite System
    Scanning Electron Microscopy Volume 1986 Number 4 Article 45 8-30-1986 Phase Transitions of Calcium Oxalate Trihydrate and Epitaxy in the Weddellite-Whewellite System Sergio Deganello University of Chicago Follow this and additional works at: https://digitalcommons.usu.edu/electron Part of the Life Sciences Commons Recommended Citation Deganello, Sergio (1986) "Phase Transitions of Calcium Oxalate Trihydrate and Epitaxy in the Weddellite- Whewellite System," Scanning Electron Microscopy: Vol. 1986 : No. 4 , Article 45. Available at: https://digitalcommons.usu.edu/electron/vol1986/iss4/45 This Article is brought to you for free and open access by the Western Dairy Center at DigitalCommons@USU. It has been accepted for inclusion in Scanning Electron Microscopy by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. SCANNING ELECTRON MICROSCOPY /1986/IV (Pages 1721-1728) 0586-5581/86$1.00+0S SEM Inc., AMF O'Hare (Chicago), IL 60666-0507 USA PHASE TRANSITIONS OF CALCIUM OXALATE TRIHYDRATE AND EPITAXY IN THE WEDDELLITE-WHEWELLITESYSTEM Sergio Deganello * Nephrology Program, University of Chicago, IL and Institute of Mineralogy, University of Palermo, Italy (Received for publication April 07, 1986, and in revised form August 30, 1986) Abstract Introduction The phase changes calcium oxalate Only rarely is calcium oxalate trihydrate-weddellite, weddellite-calcium trihydrate (COT) found in urine or in oxalate monohydrate and calcium oxalate renal calculi. Nevertheless COT has trihydrate-whewellite are individually received much attention (i.e., Gardner, examined at the atomic level from a 1975) due to the possibility that it may theoretical point of view; concomitantly be a precursor to the formation of the topological requirements necessary for whewellite (COM) and weddellite (COD) in phase stability are clarified for each human kidney stones.
    [Show full text]
  • THE NATURE of a WHEWELLITE-RICH ROCK CRUST ASSOCIATED with PICTOGRAPHS in SOUTHWESTERN TEXAS Jon Russ, Warna D
    THE NATURE OF A WHEWELLITE-RICH ROCK CRUST ASSOCIATED WITH PICTOGRAPHS IN SOUTHWESTERN TEXAS Jon Russ, Warna D. Kaluarachchi, Louise Drummond and Howell G.M. Edwards Summary—A whewellite-rich rock crust covers vast areas of limestone inside dry rock shelters and under rock overhangs throughout the Lower Pecos Region in southwestern Texas (USA). The natural rock crust, composed primarily of whewellite and gypsum with lesser amounts of quartz and silicates, encapsulates the paints of the extraordinary pictographs at more than 250 rock art sites in the region. The authors propose a model that describes the origin of each crust constituent and the evolution of these surfaces. Furthermore, they describe the relationship between the ancient paints and crust matrices, information that is necessary for the development of sound conservation strategies. Introduction The calcium oxalate minerals whewellite (CaC2O4•H2O) and weddellite (CaC2O4•(2+x)H2O) are now realized to be common on rock surfaces. The substrates on which they are known to occur include granite, marble, limestone and sandstone, as well as glass, plaster and wood. Geographically, oxalate coatings have been reported in the northern Mediterranean (Greece, Italy and Spain) [1-4], Australia [5, 6], and the southwestern United States (California [7], Utah [8] and Texas [9]). In Europe the oxalates are generally associated with stoneworks [3] but also exist on natural rock outcrops [10], including those with ancient rock paintings [11]. In Australia and the United States, the minerals have been identified on rock surfaces associated with prehistoric pictographs. The origin of whewellite and weddellite on exposed surfaces is not fully understood.
    [Show full text]