PG5 - Minerals II

PG5 - Minerals II - Is it a mineral? A naturally occurring,...

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Unformatted text preview: Is it a mineral? A naturally occurring, inorganic solid with a regular internal atomic structure and a specific chemical composition. A. YES 1.  Beer 2.  Table salt 3.  Diamond 4.  Glass 5.  Halite 6.  Ice in a glacier 7.  Ice from an ice machine 8.  Clay 9.  Pencil lead 10.  Rock candy 11.  Cubic zirconia X X X X X X B. NO X X X X X Mineral Cleavage The tendency of some minerals to break along flat surfaces Chip Clark 1 Mineral Cleavage Chip Clark Perfect cleavage of mica Atomic Structure of Halite (NaCl) Chloride ion Sodium ion 2 Different types of mineral cleavage 4 directions Octahedral cleavage Fluorite 6 directions Dodecahedral cleavage Rhombohedral cleavage. Example: CALCITE Sphalerite Fracture Breakage along irregular surfaces 3 Quartz Conchoidal Fracture Obsidian Malachite Sulfur Color Quartz Crystal 4 Rose Quartz Amethyst Citrine Smoky Quartz Milky Quartz Aventurine Hardness Resistance to scratching Devised a scale based on the ability of one mineral to scratch another Friedrich Mohs 5 Mohs hardness scale Talc – 1 Why is talc soft: A.  Covalent bonds hold the structure together B.  Internal crystals are small C.  Van der Waals bonds hold the structure together D.  Ionic bonds hold the structure together Mohs hardness scale Fragment of an alabaster statue of Amenemhat III at the Louvre Museum Gypsum – 2 Calcite – 3 6 "The Most Colorful Mineral in the World" Source of fluorine. Fluorite – 4 Apatite is a group of minerals containing OH−, F−, Cl− or Br− ions, in the crystal. Hydroxylapatite is the major component of tooth enamel. Fluorapatite resists acid better than hydroxyapatite. Toothpaste and fluoridated water contain fluoride to allow exchange in the teeth of fluoride ions for hydroxyl groups in apatite. Apatite – 5 Mohs hardness scale Feldspar – 6 Quartz – 7 7 Mohs hardness scale Topaz – 8 Corundum – 9 Sapphire Ruby 8 Mohs hardness scale Diamond – 10 Hope diamond The Sovereign's Royal Sceptre with the Cross with the Star of Africa diamond. Density Gold has a density of 20 Mass per unit volume Commonly expressed in grams per cubic centimeter. Continental crust ~2.7 Ocean crust ~ 3.0 Mantle ~ 3.3 Quartz has a density of 2.7 Galena has a density of 7.5 9 Calcite passes the ‘acid test’ Magnetism Taste Magnetite Halite Luminescence Franklin 10 Silver Gold Native Elements Sulfur Copper Oxides Hematite Cassiterite - SnO2 Spinel - MgAl2O4 11 Sulfides Sphalerite Cinnabar - HgS Pyrite Carbonates 12 Calcite What two elements are found in 90% of all minerals in the crust? A. Iron and nickel B. Iron and hydrogen C. Silicon and oxygen D. Silicon and carbon Relative Abundance of Elements 13 Silicon-oxygen tetrahedron Silicate Structures 14 Isolated Tetrahedra Olivine Single Chains (Mg,Fe)2SiO4 Double Chains 15 Pyroxene Augite (Fe,Mg)SiO3 Amphibole Hornblende Ca2(Mg,Fe,Al)5(Al,Si)8O22(OH)2 16 Comparison of Cleavages Pyroxene Amphibole Comparison of Cleavages Pyroxene Amphibole 17 Sheet Silicates Mica Sheet Silicates T O T K T O T Biotite: K Al2 [Si3AlO10] (OH)2 (coupled K - AlIV) T-layer - diocathedral (Al3+) layer - T-layer - K K between T - O - T groups is stronger than vdw 18 Muscovite Biotite Kaolinite Al2Si2O5(OH)4 Talc Mg3Si4O10(OH)2 Clay Minerals 19 Framework Silicates Feldspars Relative Abundance of Elements 20 Plagioclase Albite – Na Oligoclase – Na/Ca Labradorite – Ca Orthoclase – K KAlSi3O8 Quartz structure 21 Framework silicates Stishovite High quartz Pressure (GPa) 10 After Swamy and Saxena (1994) J. Geophys. Res., 99, 11,787-11,794. Coesite 8 6 4 2 "- quartz !- quartz Liquid Cristobalite Tridymite Low quartz 600 1000 1400 1800 2200 2600 Temperature oC Ferromagnesian Silicates Olivine Pyroxene Nonferromagnesian Silicates Chip Clark Feldspar Quartz 22 Major Rock Groups IGNEOUS SEDIMENTARY METAMORPHIC What is the difference between the three types of rocks: A. The size of the grains B. The mode of formation C. The places they are found D. The density of the rocks 23 Major Rock Groups IGNEOUS SEDIMENTARY METAMORPHIC Igneous Rocks 24 Igneous Rocks Peninsular Range Batholith Metamorphic Rocks 25 Metamorphic Rocks Sedimentary Rocks 26 27 ...
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This note was uploaded on 09/27/2011 for the course GEOGRAPHY 101 taught by Professor Vancura during the Fall '08 term at Rutgers.

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