DOC PREVIEW
USA GY 302 - Quiz 8 results

This preview shows page 1-2-14-15-30-31 out of 31 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 31 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 31 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 31 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 31 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 31 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 31 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 31 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

Quiz 8 results1: 1: Wulfenite (79%Wulfenite (79%))2:2:PurpuritePurpurite(79%(79%))3.3.VarasciteVarascite(79%(79%))4:4:WolframiteWolframite(74%(74%))5:5:Barite (53%Barite (53%))6: 6: Celestine (68%Celestine (68%))Bonus:Bonus:GibsiteGibsite(32%(32%))Average: 82.6% Highest grade: 108%A: 7B: 5C: 3D: 2F: 2GY 302: Crystallography & MineralogyGY 302: Crystallography & MineralogyUNIVERSITY OF SOUTH ALABAMALecture 21: Inosilicates 1Pyroxenes and PyroxenoidsLecture 21: Inosilicates 1Pyroxenes and PyroxenoidsClass VIII Minerals1. Sorosilicates2. Cyclosilicates (3, 4 and 6 fold coordination)Last TimeSorosilicatesMineral Formula SystemZoisite Ca2Al3O(SiO4)(Si2O7)(OH) Orthorhombic Clinozoisite Ca2Al3O(SiO4)(Si2O7)(OH) Monoclinic Epidote Ca2(Al,Fe)Al2O(SiO4)(Si2O7)(OH) Monoclinic Allanite (Ca,Ce) 2(Fe,Fe)Al2O(SiO4)(Si2O7)(OH) MonoclinicLawsonite CaAl2SiO7(OH)2·H2O OrthorhombicPumpellyite Ca2MgAl2(SiO4)(Si2O7)(OH)2·H2O MonoclinicVesuvianite (Idocrase) Ca10Mg2Al4(SiO4)5(Si2O7)2(OH)4TetragonalHemimorphite Zn4Si2O7(OH)2·(H2O) OrthorhombicHemimorphite[Zn4Si2O7(OH)2·H2O]Crystal: OrthorhombicPt. Group: 2mmHabit: massive to mammillarySG: 3.45; H: 5L: vitreous; Str: whiteCol: colorless, brown, to greyClev: perfect [001]Optics: Biaxial (+); bir=0.020 nα=1.61; nβ=1.62, nγ=1.736Sorosilicate Mineralshttp://webmineral.com/data/Hemimorphite.shtmlNamed after the hemimorphic nature of the crystals.CyclosilicatesMineral Formula SystemBeryl Be3Al2Si6O18Hexagonal “Tourmaline” (Na,Ca)(Li,Mg,Al)(Al,Fe,Mn) 6(BO3)3(Si6O18)(OH)4Hexagonal (Trigonal)Cordierite Al3(Mg, Fe)2(AlSi5O18) Orthorhombic Axinite (Ca, Mn, Fe)3Al2(BO3)Si4O12(OH) TriclinicDioptase CuSiO2(OH)2Hexagonal (Trigonal)Silicate rings come in 3, 4 and 6 fold structures. 8-fold structures also occur in nature (e.g., sulfur)Cyclosilicate Minerals 6 fold ring structureBeryl [Be3Al2Si6O18]Crystal: HexagonalPt. Group: 6/m 2/m 2/mHabit: euhedral, columnarSG: 2.76; H: 7.5-8L: vitreous; Str: whiteCol: blue, yellow, red, greenClev: imperfectOptics: Uniaxial (-); bir=0.004-0.007ne=1.564; nw=1.568Cyclosilicate Minerals (6-fold rings)http://webmineral.com/specimens/picshow.php?id=123From the ancient Greek, beryllos, signifying a "precious blue-green color of sea water" stone.Today’s AgendaClass VIII Minerals: Inosilicates (part 1)1. General Introduction to Inosilicates2. Pyroxenes3. PyroxenoidsInosilicatesThe “chain” silicates come in 2 main “flavors”Single chains (Si:O = 1:3)(Pyroxene Group)(Pyroxenoid Group)Double chains (Si:O = 1:2.5)(Amphibole Group)Inosilicates (single chain)Two major sub groups of pyroxenes are distinguished on the basis of crystal structure:1) Orthopyroxenes (orthorhombic)2) Clinopyroxenes (monoclinic)http://www.uwgb.edu/dutchs/GRAPHIC0/ROCKMIN/ATOM-STRUCT/PyroxChain.gifInosilicates (single chain: pyroxenes)General formula: XYSiO3or XY(Si,Al)2O6X[larger ions] = Ca2+, Na+, Fe2+and/or Mg2+; rarely Zn2+, Mn2+, Li+Y[smaller ions] = Cr3+, Al3+, Fe3+, Mn3+Si:O ratio is 1:3(octahedrally coordinated cations between SiO3 chains)http://www.tulane.edu/~sanelson/images/opx-cpxphasediag.gifInosilicates (single chain: pyroxenes)General formula: XYSiO3or XY(Si,Al)2O6X[larger ions] = Ca2+, Na+, Fe2+and/or Mg2+; rarely Zn2+, Mn2+, Li+Y[smaller ions] = Cr3+, Al3+, Fe3+, Mn3+Si:O ratio is 1:3(octahedrally coordinated cations between SiO3 chains produce orthorhombic or monoclinic symmetries)http://ruby.colorado.eduMonoclinic OrthorhombicInosilicates (single chain; pyroxenoids)General formula: X2SiO3X[larger ions] = Ca2+, Na+, Fe2+and/or Mg2+Si:O ratio is 1:3(larger cations force triclinicsymmetry)http://ruby.colorado.eduInosilicates (single chain)Orthopyroxene: orthorhombic minerals (5)Hypersthene, Enstatite, Ferrosilite, Donpeacorite, NchwaningiteClinopyroxene: monoclinic minerals (18)Clinoenstitite, clinoferrosilite, pigeonite, diopside, hedenbergite, spudomenePyroxenoid: Triclinic minerals (lots)wollanstonite, pectolite, rhodoniteInosilicates (single chain)Enstitite [Mg2Si2O6]Crystal: OrthorhombicPt. Group: 2/m 2/m 2/mHabit: laminar, massive, fibrousSG: 3.2; H: 5.5L: vitreous to pearly; Str: grey Col: white, yellow, brown, grayClev: [110]; [010] goodOptics: Biaxial (+); bir=0.009nα=1.65; nβ=1.65, nγ=1.66Occurrence:mafic intrusive rocksInosilicate Minerals (orthopyroxene)From the Greek enstates - "opponent."Enstitite is actually one member of a continuous series suite of “orthopyroxene” (Enstitite-Ferrosilite).http://ruby.colorado.edu/~smyth/min/images/enstatite.gifInosilicate Minerals (orthopyroxene)http://upload.wikimedia.org/wikipedia/en/4/42/Pyrox_names.png2009 textbook’s “mineral” (p265)hypersteneOrthopyroxenesEnstitite (En) can also be related to many other silicate minerals through this phase diagramInosilicate Minerals (orthopyroxene)http://web.pdx.edu/~ruzickaa/meteorites/McSween/Fo-Qz.gifThere is complete Mg-Fe solid solution between the pyroxenes, and as with most Mg-Fe solid solutions, the Mg-rich end members crystallize at higher temperatures than the Fe-rich end members. http://www.geo2all.com/vb/Inosilicate Minerals (clinopyroxenes)ClinopyroxenesThere are more options for ternary plots as there is more variability in cation composition… and you are going to ♥ the phase diagram possibilitiesAugite(Ca,Na)(Mg,Fe,Al)(Si,Al)2O6Crystal: MonoclinicPt. Group: 2/mHabit: columnar, massive, fibrousSG: 3.4; H: 5 to 6.5 L: vitreous; Str: green-greyCol: green-greyClev: perfect [110], poor [010]Optics: Biaxial (+); bir = 0.0260nα=1.68; nβ=1.684, nγ=1.706Inosilicate Minerals(clinopyroxene)From the Greek auge -"luster."http://webmineral.com/data/Augite.shtmlOccurrence: basic igneous & metamorphic rocksInosilicate Minerals(clinopyroxene)http://www.mii.org/Minerals/photoaugite.htmlFrom the Greek auge -"luster."Occurrence: basic igneous & metamorphic rocksAugite(Ca,Na)(Mg,Fe,Al)(Si,Al)2O6Crystal: MonoclinicPt. Group: 2/mHabit: columnar, massive, fibrousSG: 3.4; H: 5 to 6.5 L: vitreous; Str: green-greyCol: green-greyClev: perfect [110], poor [010]Optics: Biaxial (+); bir = 0.0260nα=1.68; nβ=1.684, nγ=1.706Inosilicate Minerals(clinopyroxene)Spodumene [LiAlSi2O6]Crystal: MonoclinicPt. Group: 2/mHabit: bladedSG: 3.15; H: 6.5-7L: vitreous; Str: whiteCol: grey-white, yellow, pinkClev: [110] perfect; [100] goodOptics: Biaxial (+); bir = 0.014-0.018nα=1.648; nβ=1.655, nγ=1.662Occurrence:Li-bearing pegmatitesFrom from the Greek, spodoumenos, "burnt to ash," alluding to its


View Full Document

USA GY 302 - Quiz 8 results

Documents in this Course
NOTES

NOTES

5 pages

Load more
Download Quiz 8 results
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Quiz 8 results and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Quiz 8 results 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?