Mineral Quiz 1 results1: Antimony (28%)2: Cinnabar (100%)3. Niccolite (28%)4: Sphalerite (94%)5: Enargite (06%)6: Stibnite (37%)2011: Average: 60.4% Highest grade: 80%2010 A 52 5% Hi h t d2011 v 2011 Mineral Quiz Results20101: Tetrahedrite (41%)2: Antimony (22%)3. Enargite (11%)4: Chalcopyrite (67%)5: Silver (48%)6: Jamesonite (37%)7: Covellite (63%)2010: Average: 52.5%Highest grade: 91%20111: Antimony (28%)2: Cinnabar (100%)3. Niccolite (28%)4: Sphalerite (94%)5: Enargite (06%)6: Stibnite (37%)2011: Average: 60.4%Highest grade: 80%GY 302: Crystallography & MineralogyGY 302: Crystallography & MineralogyUNIVERSITY OF SOUTH ALABAMALecture 14: HalidesLecture 14: HalidesLast TimeMore Oxides1. Chromite (and Chromium)2. Uraninite (and Uranium)3. Chromite formation (ultramafic intrusions)4. Uraninite formation (sedimentary, placer)5. Supergene enrichment (recap of hydrothermal emplacement)ChromiteChromite(FeCr(FeCr22OO44))Crystal: IsometricPt. Group: 4/m 3 2/mHabit: octahedral, sucrosicSG: 5.10 H: 5.5 L: metallicCol: black (brownish)Str: black (brown)Clev: none; twinning on {111}; concoidal fracture─Name derivation: From its elemental composition containing chromName derivation: From its elemental composition containing chromium ium Oxide Mineralshttp://www.theodoregray.com/PeriodicTable/Samples/Chromite/s12s.JPGOxide MineralsUraninite (UO2)Crystal: IsometricPt. Group: 4/m 3 2/mHabit: massive, botryoidalSG: 7.0-9.5H: 5.5 L: submetallic to dullCol: blackStr: brown to blackClev: none; concoidal fracture─Name derivation: From its elemental composition containing uranium Oxide Mineralshttp://www.treasuremountainmining.com/eb56uran1M.jpgOxide Mineralshttp://serc.carleton.edu/images/research_education/nativelands/UraniumDeposits.jpgSupergene enrichmentHydrothermal: a process involving “hot” water (usually groundwater under confining pressure).Epithermal: <200°C(50°C and above)Mesothermal: 200-300°CHypothermal: >300°CSupergene enrichment involves meteoric water(“cold”)Today’s AgendaHalides1. Select minerals2. Occurrences and Associations Featured minerals: EvaporitesHalidesThis class also includes bromides (ABrx) and iodides (AIx); i.e., the halogens.HalidesIodides and bromides are rather rare, but you do get them in the Cerargyrite group of Ag-compoundsAgCl: chlorargyriteAgBr: BromyriteAgI: IodryiteHalite (NaCl)Crystal: IsometricPt. Group: 4/m 3 2/mHabit: cubic, hopper crystalsSG: 2.17; H: 2.5 L: vitreous; Str: whiteCol: white (various shades)Clev: perfect [100], [010], [001]Optics: Isotropic (n=1.544)─Name derivation: From the Greek halos (salt) Halide MineralsHalite (NaCl)Occurrence: the most common soluble evaporite mineralAssociated Mins: calcite (limestone), dolomite (dolostone), gypsum, anhydrite, sulfur (salt diapirs)May be confused with:sylvite Uses:Kentucky Fried ChickenHalite MineralsSalt (data in kilo tonnes)Halide MineralsSource: USGS Mineral Commodity Summaries 2011Salt (US data)Halide MineralsSource: USGS Mineral Commodity Summaries 2011Sylvite (KCl)Crystal: IsometricPt. Group: 4/m 3 2/mHabit: cubic, hopper crystalsSG: 1.99; H: 2.5 L: vitreous; Str: whiteCol: white (various shades)Clev: perfect [100], [010], [001]Optics: Isotropic (n=1.4903)─Name derivation: named after Dutch chemist Sylvia de la Boe (1614-1672) Halide MineralsSylvite (KCl)Occurrence: potash deposits (evaporite basins); much less common than halite of which it is always mixed with.Associated Mins: halite, gypsumMay be confused with: halite (distinguished because of its sectility)Uses:fertilizer (potash)Halite MineralsCarnalite (KMgCl3·6H2O)Crystal: OrthorhombicPt. Group: 2/m 2/m 2/mHabit: massive, fibrous, hexagonalSG: 1.6; H: 2.5 L: greasy (deliquescent); Str: whiteCol: variable (white, grey, reddish)Clev: none/indistinctOptics: biaxial+nα= 1.467; nβ= 1.475; nγ= 1.494Name derivation: after a German mining engineer Halide Mineralshttp://webmineral.com/data/Carnallite.shtmlCarnalite (KMgCl3·6H2O)Occurrence: evaporite depositsAssociated Mins: halite, sylviteMay be confused with:sylvite, haliteUses:fertilizer/potash oreHalite Mineralshttp://www.dmr.go.th/images/info/mineral/carnallite_1.jpgPotash (data in kilo tonnes)Halide MineralsSource: USGS Mineral Commodity Summaries 2011Potash (US data)Halide MineralsSource: USGS Mineral Commodity Summaries 2011Rocanville Potash Mine, Saskatchewan, CanadaHalide MineralsLocation: Saskatchewan, CanadaOwnership: Potash Corporation of Saskatchewan (100%)Geology type: Devonian evaporite sequencesMineral type: Sylvite, carnallite, halite and clayReserve base: 372Mt mineable; 1,132Mt inferred resourceAnnual production: 7.5Mt of ore and 2.57Mt of potash products (2005)Mining method: Underground long room-and-pillar, using two- and four-rotor continuous minersProcessing method: Crushing, desliming, cyclones, flotationEmployment: 340Key Equipment:Underground: Marietta two- and four-rotor continuous minersConcentrator: Allen Bradley central control systemhttp://www.mining-technology.com/projects/rocanville/Subsurface potash deposits in Sask.Halide Mineralshttp://www.ags.gov.ab.ca/publications/wcsb_atlas/A_CH10/FG10_18.GIFFluorite (CaFFluorite (CaF22))Crystal: IsometricPt. Group: 4/m 3 2/mHabit: cubic, octahedral crystalsSG: 3.0-3.25; H: 4 L: vitreous; Str: whiteCol: variableClev: [111] perfectOptics: Isotropic (n=1.434)─Name derivation: From its elemental composition containing fluorName derivation: From its elemental composition containing fluorineineHalide Mineralshttp://www.electric-lady-land.com/004.%20Fluorite-LW.jpgFluorite (CaFFluorite (CaF22))Occurrence: epithermal veins (Mississippi Valley ore deposits). Associated Mins: widespread; dolomite, calcite, sphalerite, galenaMay be confused with:calciteUses:metal fluxes (Al and Fe); chemical industryHalite Mineralshttp://webmineral.com/specimens/Fluorite.jpgCryolite (Na3AlF6)Crystal: MonoclinicPt. Group: 2/mHabit: massive to prismaticSG: 2.97H: 2.5-3 L: vitreous to greasyOptics: Anisotropic (biaxial)Col: variable (white, grey, reddish)Str: whiteClev: noneName derivation: From the Greek kryos meaning “frost”Halide MineralsCryolite (Na3AlF6)Occurrence: rare, pegmatite intrusion (Greenland); one other deposit in RussiaAssociated Mins: Greenland: microcline, quartz, siderite, fluoriteMay be confused with:just about everythingUses: Al refining (electrolysis). Now artifically made from FluoriteHalite MineralsEvaporite
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