 | | Journal (article/letter/editorial) | | and sedimentary interbeds ofthe Columbia RiverBasalt Group (CRBG) in central Washington State, USA....is diverse,with silica minerals that includeopal-A,opal-CT, chalcedony, and macrocrystalline quartz...commonly, specimens contain multiplephases.Opal-A andOpal-CT often coexist. Some woods are mineralized...macrocrystalline quartz are common as minor constituents inopal wood.In these specimens, crystalline silica filling...vessels open. Diagenetic transformation ofopal-A toopal-CT in fossil wood has longbeen a widely accepted |  | | Journal (article/letter/editorial) | | T H E STORY OFOPALByG. FREDERICKSHEPHERDTechnical Assistant In Geology - (1932)Museum of Science...Science and Industry, Chicago, IllinoisOpalAnEvilOmen?It is most deplorable that the mind ofthe...the magnificent and ever-changing beauty of theopal to be maligned with puny superstition. Many objects...misunderstanding, ungrounded report, or superstition, and theopal is oneof them — with little, if any, reason for...forthe spread of its ill-fated powers.Theopal has not always been thoughtof as being unlucky, and it |  | | Book (volume) | | reserved.H.,Hofbuchdruckerei, Cothen-Anhalt (Germany). PRECIOUSThePreciousStones.Preciousothers...instance,speciesandcoloureddifferentlyanlargelyandonofallorother minerals....inbrightafound inareandtransparentopal, cat’s-eyeordefinecertainmosthaveoccurrence...StonesSTONES.theshalldescriptionincludeandealing with rockThe mineralswhichsectionwill...substancesandtocomparedofhigheranglelessanbrilliantsandthenumberarefront,material; |  | | Journal (issue) | | mmigration Ol ice.Opal Mines, Wbite Cllifs, New South Wales.Oourte8JISpecialOpal NuinberGranite and...magazine•.'-============================ rROCH. San dMINERALSA NON-TECHNICAL MAGAZINE--'ON-MINI...1Iuseum. B y 1rilli<1m F. FoshagThe Geology ofOpal. By, Oilb rrt Hart.. . . . . . . . . . . . . ....Quest of theOpal. B!I If. T. Strnng.. . ....................... . .('(}Jor Play inOpal. B.11, Il. E... . . . . . . . . . . . . . . . . . . . . .'fbeOpal. JJy E11,qe11e Jr. B1"11k..................... |  | | Journal (article/letter/editorial) | | sität, Jena,GermanyMineralogisches Institut, TU Bergakademie Freiberg/Saxony,Germanya r t i c l...ImpactiteTektiteFrictioniteFulguriteBuchiteOpalGlass propertiesa b s t r a c tVitreous materials...Republic;3rd in 1996 at the University of Jena,Germany, 4th in 2002 inLyon, France), as well as the Interdisciplinary...Compared to industrial glasses, natural glasses haveanessential advantage in terms of their lifespan in...of a final toxic-waste deposit. Thedevelopment ofan adequate technology for final waste disposal isa |  | | Journal (issue) | | d i e scutting Petersburg granite in the Dalequarry (Figure 1). Clearglassy areas within the crystals...gems (Frank Crayton, personal communication). Thequarry isoperated by Tarmac Inc.Powhutcan County - Clear...Golden beryl has also been found inthe residuum abovean alaskite d i e along a ridge crest about 0.5miles...Tract ,(Dunlap)mine. The chrysocolla is :generallyan intenseblue color and is often associated with greer...inpegmatite,largest crystal 3 inches long,Dalequarry, ChestefieldCounty(photograph by T. M. Gathright |  | | Book | | in Adamello Massif, Central Southern Alps,Italy:An Investigation of Its Mineralogy, Crystallography...and Allan PringA Review of the Classification ofOpal with Reference to Recent New LocalitiesReprinted...Economic Geologyfrom the University of Hamburg (Germany), where he also served as a Visiting Professor...collaborative research projects worldwide. IanGraham is alsoan Associate Editor of Mineralogical Magazine and the... is positioned between academia and industry.Asan applied science, in gemology, the instruments used |  | Fetherston, J. Michael, Stocklmayer, Susan M., Stocklmayer, Vernon C., Fetherston, J.M., Stocklmayer, S.M., Stocklmayer, V.C. (2013) Gemstones of Western Australia.Mineral Resources Bulletin 25 (1st ed.). Geological Survey of Western Australia | Report (edition) | | .......................... 108Chapter 13Opal109Opal — gemstone properties .................................................................. 109Opal terminology ........................................................................ 110Preciousopal in Western Australia ................................................................. 113Commonopal ...................................................................................... 114Commonopal in Western Australia........................... |  | | Journal (article/letter/editorial) | | historical point of view. Niceyellowish-red color fireopal and common opals from these islands are also very...Streymoy. Parent rocks are represented bythe “middlebasalt” formation. Investigated opals generally show vitreous-dull...variable growth rates.Key words: Faroe Islands,opal, magmatism, trace elements, phosphorous, XRD, SEM...species like apophyllite, calcite, cristobalite,opal, chalcedony and native copper (Jørgensen 2006, Ghizzoni...historical pointof view; nice yellowish-red color fireopal and commonopals have been frequently found in |  | Gaines, Richard V., Skinner, H. Catherine W., Foord, Eugene E., Mason, Brian, Rosenzweig, Abraham, King, Vandall T. (1997)Dana's New Mineralogy (8th ed.). Wiley-Interscience. p.1872 | Book (edition) | | role in naming the plants and animals, also showedan interest in classifying the minerals. His natural...synonymy was improved and extended. The work becamean internationalclassic for over 50 years, due to the...Fritz: Bergakademie Freiberg, Freiberg, Saxony,Germany.Donald B. Hoover: U.S.G.S., Federal Center, Lakewood...Institut fur Mineralogie, Ruhr Universitat Bochum,Germany.Duane Mellor: Geology Library, Yale University...Berlin,Germany.Peter Susse: MINABS, Inst. of Mineralogy, Univ. of Gottingen, Gottingen,Germany.C. Sheldon |  | Swayze, G. A., Clark, R. N., Goetz, A. F. H., Livo, K. E., Breit, G. N., Kruse, F. A., Sutley, S. J., Snee, L. W., Lowers, H. A., Post, J. L., Stoffregen, R. E., Ashley, R. P. (2014) Mapping Advanced Argillic Alteration at Cuprite, Nevada, Using Imaging Spectroscopy.Economic Geology, 109 (5) 1179-1221doi:10.2113/econgeo.109.5.1179 | Journal (article/letter/editorial) | | hydrothermalalteration. Partial lichen cover onopal spectrally mimics chalcedony, limiting its detection...Kerr et al., 2011). Spectroscopy isalso playingan increasing role in analyses of alteration in drill...near-infrared (VIS-NIR or VNIR-SWIR)0.4- to 2.5-μm range isan effective tool for evaluating subtle patterns of...StonewallMountainHi37 o 30'Figure 2CupriteoanyonInferredcalderamargin266117 15'ckPa...rhyolitic ashflow and airfall tuffs, conglomerate, andbasalt (Fig. 3). Forconvenience, the foci of the two |  | | Journal (article/letter/editorial) | | silica coating on youngbasalt from Kilauea, Hawaii, as well as hyalite (opal-AN),silica sinters, and...silica gels and silicic acid. Pulse delays of up toan hour were employedfor silica samples with slow spin...secondary phase invarious geological environments.Opal is common in neutral-pHhydrothermal settings, where...coatings formedby acid-sulfate alteration of Hawaiianbasalt.NMR has been applied to various aspects of the...reportedanadditional, smaller peak due to silicons with single attached OHgroups (Q3) in someopal-CT samples |  | | Book (volume) | | concerned,Ohio is unique in but a single gemstone,an exceptionally high quality, colorful flint that is...chert, translucent chalcedony, jasp-agate and commonopal, rivaling inbeauty the Arizona agatized wood. This...the western counties,especially the Clay CenterQuarry 12 miles southeast of Toledo but in Ottawa Co....jct. of Brint St. and Centennial rd., the MedusaQuarry (SW of 4quarries), very many specimens⎯fossils...deposits⎯Hematite.OTTAWA COUNTYCLAY CENTER, area limestonequarry, famed⎯Calcite, Celestite (fluorescent),Dolomite |  | | Book (volume) | | concerned,Ohio is unique in but a single gemstone,an exceptionally high quality, colorful flint that is...chert, translucent chalcedony, jasp-agate and commonopal, rivaling inbeauty the Arizona agatized wood. This...the western counties,especially the Clay CenterQuarry 12 miles southeast of Toledo but in Ottawa Co....jct. of Brint St. and Centennial rd., the MedusaQuarry (SW of 4quarries), very many specimens⎯fossils...deposits⎯Hematite.OTTAWA COUNTYCLAY CENTER, area limestonequarry, famed⎯Calcite, Celestite (fluorescent),Dolomite |  | | Book (edition) | | great changes of emphasisin mineral collecting andan unforeseen growth in the num-ber of collectors...Africa, and Asiahave become significant sources.An increasing recognitionof investment values in fine...carefully preserved to arrive on a dealer's shelf inan unblemished state.Would that the old-time miners...common can't-be-bothered attitude can be replaced byanenlightened recognition of the operators' public...insurance coverage for the protection of the mine andquarry operators.The writer wishes to express his appreciation |  | | Book | | Zimbabwe Bruce Cairncross Published by Struik Nature (an imprint of Penguin Random House South Africa (Pty)...interest in the subject. Minerals and gemstones arean important part of our outstanding geological and...rather than the southern African region as a whole.An early exception is Mciver (1966), Gems, Mineralsand...or economic ore samples. Discretion (and possiblyan element of personal bias) was used to select which...summarized in the table above. As can been seen, there isan evolutionary trend over time in the genesis of mineral |  | | Book (volume) | | review of deposits, a helpful geographicalindex, andan exceptionally complete listing of books andarucles...America has developed into amajor exporter rather thanan importer.A VAN NOSTRANDREINHOLDBOOK . Digitized...AMERICAIn Iwo VolumesVolume |JOHN SINKANKAS[aN] VANNewNOSTRANDYorkCincinnatiREINHOLDToronto...neaterie ra8‘y-ml3eepon*:c=:anvi5=fii?iaj—»yay_—’*:...loan of photographs of TampaBay silicified coral.An outstanding compilation of Mexican gemstone information |  | | Book (volume) | | half miles south of Cape Wrath, nearSutherland.an outlier of Torridon Conglomerate, in small veins...filamentous net-work is here brown.Ayrshire. At LaggQuarry, Fisherton, Ayr.The mossy or stalactiticsurrounded...porphyriticstone.::Liulithgowshire inan opening near the oldquarry of Kirkton,masses in limestone of...since elapsed he collectedDuring the time that hasan exceptionally large number of specimensfrom almost...reference at the Edinburgh Museum ofScience and Art.Inan Appendix references are given to information which |  | | Book (volume) | | Plains, wellsdrilled deep into this unit providean inexhaustible supply of cold artesian, Rocky Mountain...banks, tributarygravels, etc.petrified wood, woodopal.CORSON COUNTYLITTLE EAGLE: area ridges, slopes...slopes, stream beds, etc. petrified wood, woodopal; along the Grand R. though entire Co., regional...banks, breaks, gravels, etc.petrified wood, woodopal.438 A Location Guide for Rock Hounds in the...minesColumbite, Gold,Silver, etc.; and (2) Old MarbleQuarry on the Needles Hwy. 5.5 mi. NEScheelite, anddeep |  | Lee, M. R., MacLaren, I., Andersson, S. M. L., Kovács, A., Tomkinson, T., Mark, D. F., Smith, C. L. (2015) Opal-A in the Nakhla meteorite: A tracer of ephemeral liquid water in the Amazonian crust of Mars.Meteoritics & Planetary Science, 50 (8) 1362-1377doi:10.1111/maps.12471 | Journal (article/letter/editorial) | | Nr 8, 1362–1377 (2015)doi: 10.1111/maps.12471Opal-A in the Nakhla meteorite: A tracer of ephemeral...Forschungszentrum J€ulich GmbH,52425 J€ulich,Germany4Scottish Universities Environmental Research...its principal constituents arenanoparticles ofopal-A. This hydrous and amorphous phase precipitated...respect to silica by dissolution of olivine.Eachopal-A nanoparticle is enclosed within a ferrihydrite...nanoparticles andolivine. The fluids that formed both theopal-A/ferrihydrite and the siderite were sourcedfrom | | | Book (edition) | | great changes of emphasis in mineral collecting andan unforeseen growth in the number of collectors. Mineral...Africa, and Asia have become significant sources.An increasing recognition of investment values in fine...carefully preserved to arrive on a dealer's shelf inan unblemished state. Would that the old-time miners...apply pressure-through the press, simple consciencean d good will, or as stockholders-to encourage mine...conunon can't-be-bothered attitude can be replaced byan enlightened recognition of the operators' public |  | | Book | | •• •••':. Ranson1 ,Jay E .Gemsan d minerals of Arnerica549 . 075 RAiJSO rtiSAUSALITO...Gemstones and Minerals;Volcanic Flows; Values inan Outcrop4. Preparation for Field Collecting52...Petrified Wood131Characteristics of Agates;Opal, Queen of the Gems; Petrified Wood;Commonly Occurring...Family GemstonesThe Various Names and Forms of AgateOpal and Its VarietiesRecommendations for Use of Polishing...printer, typographer, and publisherknows full well,an error-free reference work is as rare as feathers |  | | Journal (article/letter/editorial) | | correlation with silicon content, as does 6’*0.Opal from bothsponge spicules and sinters is light,...occur during the low temperatureprecipitationofopal and, possibly, poorly ordered phyllosilicates,with...d3’Si values are largely inherited,but the primaryopal 630Si values can be modified by isotopic equilibration...and dissolvedsilicon during the transformationofopal into quartz.INTRODUCTIONIN the 1950’s, variations...22.86 cm. radius Nier-typemassspectrometerwithan all metal sample introductionsystem,except for |  | | Book | | For all thei.r skiUs and expertise - wor1h more th,an gold were the.y.We also must ac.knowle.dg-e, f,o...one's favourite specimens for thispublication. Notan easy task.As the current chairman of SMLS I hope...Meschede, Sauerland, North Rhine - Westphalia ,Germany . Photo: John Hall SMLS MEMBERS' FAVOURITESThis...hydraulicshaft in the Smallcleugh Mine and we boughtan inflatable dinghy so we could land on Sgurr nam Boe...something from each field trip. Thus I have accumulatedan eclectic collection of rocks, mineralsand fossils |  | Slack, J. F., Dumoulin, J. A., Schmidt, J. M., Young, L. E., Rombach, C. S. (2004) Paleozoic Sedimentary Rocks in the Red Dog Zn-Pb-Ag District and Vicinity, Western Brooks Range, Alaska: Provenance, Deposition, and Metallogenic Significance.Economic Geology, 99 (7) 1385-1414doi:10.2113/gsecongeo.99.7.1385 | Journal (article/letter/editorial) | | elements and rareearth elements has been published onan unaltered blackshale sequence hosting a major stratiform...composed mainly of Devonian to Jurassic gabbro,basalt,and ultramafic rocks of oceanic affinity. Tectonically...alternating limestone and thin-bedded calcareous shale andan upper Ikalukrok unit composed mostly ofblack shale...calcareous felsic tuff with clasts of amygdaloidalbasalt(?) to tuffaceous calcite-rich shale. Dark green...the low-iron nature of the Kayak Shale, which hasan average Fe/Ti ratio of6.25 ± 2.91, compared with |
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