Mineral List Observed in lab: Name Formula Crystal System Hand specimen Thin section

Transcription

1 Igneous Minerals (Labs 3 & 9) Framework Silicates (Tectosilicates) The SiO 4 tetrahedrons are linked together in three-dimensional forming a framework silicate where the Si:O ratio is 1:2. SiO 2 Group 1. Quartz SiO2 Hexagonal yes yes Feldspar Group K-Feldspar series 2. Microcline KAlSi 3 O 8 Triclinic yes yes 3. Orthoclase KAlSi 3 O 8 Monoclinic yes yes 4. Sanidine (K, Na)AlSi 3 O 8 Monoclinic yes yes Plagioclase series(ca, Na)(Al,Si) 4 O 8 5. Albite NaAlSi 3 O 8 Triclinic yes yes 6. Anorthite CaAl 2 Si 2 O 8 Triclinic yes yes Chain Silicates (Inosilicates) The SiO 4 tetrahedrons are arranged in single and double chains. The ratio in the single chains is 1:3 and in the double chains is 4:11. Pyroxene Group Single Chain Clinopyroxene series 7. Diopside (Ca,Mg) 2 Si 2 O 6 Monoclinic yes no 8. Augite (Ca, Mg, Fe, Na)(Mg,Fe,Al)(Al,Si) 2 O 6 Monoclinic yes yes Orthopyroxene series 9. Enstatite (Mg,Fe) 2 Si 2 O 6 Orthorhombic yes yes Amphibole Group Double Chains 10. Hornblende (K,Na) 0-1 (Ca,Na,Fe,Mg) 2 (Mg,Fe,Al) 5 (Si,Al) 8 O 22 (OH) 2 Monoclinic yes yes Isolated Tetrahedral Silicates (Nesosilicates) The SiO 4 tetrahedrons are isolated. Characterized by Si:O ratio of 1:4. Olivine (Mg,Fe) 2 SiO Forsterite Mg 2 SiO 4 Orthorhombic yes yes 12. Fayalite Fe 2 SiO 4 Orthorhombic Zircon ZrSiO 4 Tetragonal yes yes 14. Topaz Al 2 SiO 4 (F,OH) 2 Orthorhombic yes yes The SiO 4 tetrahedrons are linked together in two-dimensional sheets. The Si:O ratio in the phyllosilicates is 4:10. Mica Group 15. Biotite K(Mg,Fe) 3 (AlSi 3 O 10 )(OH) 2 Monoclinic yes yes 16. Muscovite KAl 2 (AlSi 3 O 10 )(OH) 2 Monoclinic yes yes 17. Lepidolite K(Li,Al) 2-3 (AlSi 3 O 10 )(OH,O,F) 2 Monoclinic yes no Ring silicates (Cyclosilicates) The ring silicates contain rings of linked SiO 4 tetrahedra having a ratio of Si:O = 1: Beryl Mg 6 (Si 4 O 10 )(OH) 8 Hexagonal yes no 19. Tourmaline (Na,Ca)(Li,Mg,Al) 3 (Al,Fe,Mn) 6 - Hexagonal yes no (BO3) 3 (Si 6 O 18 )(OH) 4 Phosphates 20. Apatite Ca 5 (PO 4 ) 3 OH Hexagonal yes no Geosci 301 Page 1

2 Igneous Minerals (Labs 3 & 9) cont'd 21. Magnetite Fe 3 O 4 Isometric yes no 22. Corundum Al 2 O 3 Hexagonal yes no Sulfides 23. Pyrite FeS 2 Isometric yes no 24. Pyrrohotite Fe 1-x S Monoclinic/Hexago yes no 25. Molydenite MoS 2 Hexagonal yes no Sedimentary Minerals (Lab 10) Carbonates Minerals in the carbonate group are very common and widespread. All carbonates contain (CO 3 ) -2 anionic group, which i planar structure with 1 C atom surrounded by 3 O atoms. Calcite and dolomite are the most common carbonates. Calcite Group 26. Calcite CaCO 3 Hexagonal yes yes 27. Siderite FeCO 3 Hexagonal yes no Dolomite Group 28. Dolomite CaMg(CO 3 ) 2 Hexagonal yes no Aragonite Group 29. Aragonite CaCO 3 Orthorhombic yes yes 30. Hematite Fe 2 O 3 Hexagonal yes (yes) Hydroxides The hydroxide minerals all contain OH - as an essential anion. Bauxite is not a true mineral and refers to a mixture of Al o and hydroxides. Limonite refers to a mixture of Fe oxides and hydroxides. Goethite Group 31. Goethite FeO(OH) Orthorhombic yes no 32. Limonite FeO-OH-nH 2 O (mixture of minerals yes no 33. Bauxite mixture of Al oxides & hydroxides (mixture of minerals yes no Halides Halides are characterized by the dominance of the halogen ions Cl-, Br-, F- and I Halite NaCl Isometric (cubic) yes no 35. Sylvite KCl Isometric (cubic) yes no 36. Flourite CaF 2 Isometric (cubic) yes no Sulfates Sulfate minerals are divided into two groups: the anhydrous sulfates and hydrous sulfates. Anhydrous Sulfate Group 37. Celestine SrSO 4 Orthorhombic yes no 38. Anhydrite CaSO 4 Orthorhombic yes no 39. Barite BaSO 4 Orthorhombic yes no Hydrous Sulfate Group 40. Gypsum CaSO 4 2H 2 O Orthorhombic yes no Geosci 301 Page 2

3 Sedimentary Minerals (Lab 10) cont'd Framework Silicates (Tectosilicates) The SiO 4 tetrahedrons are linked together in three-dimensional forming a framework silicate where the Si:O ratio is 1:2. SiO 2 Group 41. Chert Microcrystalline SiO 2 yes no 42. Opal SiO 2 nh 2 O amorphous yes no Zeolite Group 43. Stilbite NaCa 2 Al 2 Si1 3 O 36 14H 2 O Monoclinic yes no The SiO 4 tetrahedrons are linked together in two-dimensional sheets. The Si:O ratio in the phyllosilicates is 4:10. X-ray analysis is often necessary to tell clay minerals apart. Clay Mineral Group 44. Kalonite Al 4 (Si 4 O 10 )(OH) 8 Triclinic yes no 45. Montmorillonite (Na, Ca)(Al, Mg) 2 (Si 4 O 10 )-(OH) 2 nh 2 O Monoclinic yes no Metamorphic Minerals (Lab 11) Isolated Tetrahedral Silicates (Nesosilicates) The SiO 4 tetrahedrons are isolated. Characterized by Si:O ratio of 1:4. Garnet Group A 3 B 2 (Si 3 O 12 ) Isometric yes yes 46. Almandine Fe 3 Al 2 (Si 3 O 12 ) Isometric 47. Grossular Ca 3 Al 2 (Si 3 O 12 ) Isometric 48. Andradite Ca 3 Fe 2 (Si 3 O 12 ) Isometric Al 2 SiO 5 Group 49. Kyanite Al 2 SiO 5 Triclinic yes yes 50. Andalusite Al 2 SiO 5 Orthorhombic yes yes 51. Sillimanite Al 2 SiO 5 Orthorhombic yes no Staurolite Fe 3 Al 9 Si 23 (OH) Monoclinic yes yes Paired Tetrahedral Silicates (Sorosilicates) Paired tetrahedral silicates are characterized by isolated double tetrahedral groups. Two SiO 4 tetrahedra are joined and share an oxygen (Si 2 O 7 ). In the case of epidote, clinozoisite and vesuvianite, there are both paired and unpaired (SiO 4 ) 4- tetrahedral. Epidote Group 53. Epidote Ca 2 (Al,Fe)Al 2 Si 3 O 12 (OH) Monoclinic yes no Chain Silicates (Inosilicates) The SiO 4 tetrahedrons are arranged in single and double chains. The ratio in the single chains is 1:3 and in the double chains is 4:11. Pyroxenoid Group Single Chain 54. Wollastonite CaSiO 3 Triclinic yes yes Amphibole Group Double Chain Tremolite Series 55. Tremolite Ca 2 Mg 5 Si 8 O 22 (OH) 2 Monoclinic yes no 56. Actinolite Ca 2 (Mg,Fe) 5 Si 8 O 22 (OH) 2 Monoclinic yes no Riebeckite Series 57. Glaucophane Na 2 Mg 3 Al 2 Si 8 O 22 (OH) 2 Monoclinic yes yes Geosci 301 Page 3

4 Metamorphic Minerals (Lab 11) cont'd The SiO 4 tetrahedrons are linked together in two-dimensional sheets. The Si:O ratio in the phyllosilicates is 4:10 Perkins (2002) classifies talc and pyrophyllite with clay minerals because of their similar chemistry. Talc and pyrophyllite are sometimes considered part of the serpentine group. Clay Mineral Group 58. Talc Mg 3 (Si 4 O 10 )(OH) 8 Monoclinic yes no Chlorite Group 59. Chlorite (Mg,Fe,Al) 3 (Al,Si) 4 O 10 (OH) 8 Monoclinic yes yes Serpentine Group 60. Antigorite Mg 6 Si 4 O 10 (OH) 8 Monoclinic yes no Native Elements The native elements are divided into three groups: (1) metals, (2) semi-metals, and (3) nonmetals. Nonmetals 61. Graphite C Hexagonal yes no Economic Minerals (Lab 12) Sulfides The majority of ore minerals fall into the sulfide group. The general formula for the sulfides is (m) X (n) where A is the metallic ion and X is sulfur or more rarely selenium, tellurium, arsenic or antimony. The minerals that contain semimetals arsenic and antimony in place of the metal ions are often separated out as a related mineral group called sulfosalts. A 2 X type 62. Bornite Cu 5 FeS 4 Tetragonal yes no AX type 63. Galena PbS Isometric yes no 64. Sphalerite (Zn,Fe)S Isometric yes no 65. Chalcopyrite CuFeS 2 Tetragonal yes no 66. Covellite CuS Hexagonal yes no 67. Cinnabar HgS Hexagonal yes no 68. Realgar AsS Monoclinic yes no 69. Orpiment As 2 S 3 Monoclinic yes no Native Elements The native elements are divided into three groups: (1) metals, (2) semi-metals, and (3) nonmetals. All native metals have similar properties: metallic luster, high thermal and electrical conductivity, malleability, and opaqueness to light. Metals Gold Group: 70. Gold Au Isometric yes no 71. Silver Ag Isometric yes no 72. Copper Cu Isometric yes no Platinum Group: 73. Platinum Pt Isometric yes no Nonmetals 74. Sulfur S Orthorhombic yes no 75. Diamond C Isometric yes no Geosci 301 Page 4

5 Economic Minerals (Lab 12) cont'd Sulfates, Tungstates, Molybdates The sulfates have the general formula A m (XO 4 ) p Z q, where A is commonly a metal or semimetal, X is sulfur (or molybdenum or tungsten), and Z is an OH- group. Molybdates and Tungstates AXO Scheelite CaWO 4 Tetragonal yes no The oxides make up a large class of minerals characterized by one or more cations, usually metals, combining with oxygen. can be conveniently classified on the basis of their A:X ratio. A 2 X Type 77. Cuprite Cu 2 O Isometric yes no AB 2 X 4 Type Spinel Group 78. Chromite FeCr 2 O 4 Isometric yes yes Carbonates 79. Malachite Cu 2 (CO 3 )(OH) 2 Monoclinic yes no 80. Azurite Cu 3 (CO 3 ) 2 (OH) 2 Monoclinic yes no Phosphates 81. Turquoise CuAl 6 (PO 4 ) 4 (OH). 8 4H 2 O Triclinic yes no (rarely forms crystals) Geosci 301 Page 5