Mineral Classification.pdf

Lec 9: Mineral Classes Geol 103: Elementary Mineralogy  Systematic mineralogy Identification and classification of minerals by their properties Lec 9: Mineral Classes  Mineral classification basis Chemical composition: bas...

Lec 9: Mineral Classes Geol 103: Elementary Mineralogy  Systematic mineralogy Identification and classification of minerals by their properties Lec 9: Mineral Classes  Mineral classification basis Chemical composition: based on anion Internal structure Lec 9: Mineral Classes  based on Mineral class anion based on Mineral family chemical type based on Mineral group structural similarity same Mineral species structure but presence of Mineral variety different chemistries unusual amounts of chemical constituents Lec 9: Mineral Classes  Non- silicates Minerals that do not have a silica tetrahedron Lec 9: Mineral Classes  Non- Silicate General Chemistry Native elements 1 element Sulfides Metal + sulfur Sulfosalt Metal + semi- metal Oxide Metal + oxygen Hydroxide Metal + OH or H2O Halide Metal + halogen Carbonate Metal + CO3 Sulfate Metal + SO4 Lec 9: Mineral Classes  Other Non- Silicate General Chemistry Phosphate Metal + PO4 Arsenate Metal + AsO4 Vanadate Metal + VO4 Nitrate Metal + NO3 Borate Metal + BO3 Tungstate Metal + WO4 Molybdate Metal + MoO4 Lec 9: Mineral Classes  Native elements General chemistry: 1 element Native metals, native semi- metals, native non- metals Lec 9: Mineral Classes  Generally dense, soft, malleable, ductile, Native metals sectile, low melting points, metallic luster Groups: gold, iron, platinum Iron (Fe) Gold (Au) Silver (Ag) Platinum (Pt) Copper (Cu) Lec 9: Mineral Classes  Sheeted structure Native semi- metals Generally brittle, poorer conductors of heat and electricity, good cleavage Arsenic (As) Bismuth (Bi) Lec 9: Mineral Classes  Generally brittle, not malleable, poor Native non- metals heat and electricity conductor Sulfur (S) Graphite (C) Diamond (C) Lec 9: Mineral Classes  Sulfides General chemistry: metal + sulfur Majority of ore minerals Generally opaque, distinct color, colored streaks Bonding: ionic, metallic, covalent Lec 9: Mineral Classes  Orpiment (As2S3) Cinnabar (HgS) Galena (PbS) Sphalerite (ZnS) Realgar Bornite (AsS) (Cu5FeS4) Lec 9: Mineral Classes  Covellite (CuS) Chalcocite (Cu2S) Chalcopyrite (CuFeS2) Pyrite (FeS2) Molybdenite (MoS2) Stibnite (Sb2S3) Lec 9: Mineral Classes  Unoxidized sulfur mineral that is structurally Sulfosalt distinct from a sulfide Semi-metals take place of sulfur in the structure Considered as double sulfide Enargite Luzonite (Cu3AsS4) (Cu3AsS4) Lec 9: Mineral Classes  Oxide General chemistry: metal + oxygen Strongly ionic bonding Great economic importance Generally hard, dense, refractory Group: hematite, rutile, spinel Lec 9: Mineral Classes  Hematite (Fe2O3) Corundum (Al2O3) Rutile (TiO2) Chromite Ilmenite (FeCr2O4) (FeTiO3) Cuprite (Cu2O) Lec 9: Mineral Classes  Pyrolusite Zincite Magnetite (MnO2) (ZnO) (Fe3O4) Lec 9: Mineral Classes  Hydroxide General chemistry: metal + (OH)- or H2O Weaker bond strength than oxides Lower hardness and density Lec 9: Mineral Classes  Goethite (αFeO(OH)) Manganite (MnO(OH)) Bauxite (mixture of Diaspore diaspore, gibbsite, (αAlO(OH)) boehmite) Lec 9: Mineral Classes  Halides General chemistry: metal + halogen Highest possible symmetry Purely ionic bonding Generally low hardness, moderate to high melting points, poor heat and electricity conductor (in solid state) Lec 9: Mineral Classes  Fluorite (CaF2) Sylvite (KCl) Halite (NaCl) Lec 9: Mineral Classes  Carbonates General chemistry: metal + CO3 Strongly bonded units and do not share oxygen with each other Groups: calcite, aragonite, dolomite, monoclinic with (OH) 2H+ + CO3 → H2O + CO2 Lec 9: Mineral Classes  Calcite Aragonite Dolomite (CaCO3) (CaCO3) (CaMg(CO3)2) Lec 9: Mineral Classes  Azurite (Cu3(CO3)2(OH)2) Magnesite (MgCO3) Siderite (FeCO3) Rhodochrosite (MnCO3) Malachite (Cu2CO3(OH)2) Lec 9: Mineral Classes  Sulfates General chemistry: metal + SO4 Anhydrous and hydrous sulfates Variable characteristics but may be soluble and fluorescent Common in evaporite environments Lec 9: Mineral Classes  Barite (BaSO4) Anhydrite (CaSO4) Gypsum (CaSO4 2H2O) Lec 9: Mineral Classes  Fundamental unit: SiO4 Silicates 25% of known minerals; 90% of earth’s crust Forms in various environments 45% 40% 35% 30% 25% 20% 39% 15% 10% 5% 12% 12% 11% 8% 5% 5% 5% 3% 0% Plagioclase Alkali Quartz Pyroxene Amphibole Mica Clay Other Non- feldspar silicates silicates Lec 9: Mineral Classes  Silicate Group AKA Si-O Ratio Nesosilicate Island silicate 1:4 Sorosilicate Bowtie silicate 2:7 Cyclosilicate Ring silicate 1:3 Inosilicate Single chain silicate 1:3 Double chain silicate 4:11 Phyllosilicate Sheet silicate 2:5 Tectosilicate Framework silicate 1:2 Lec 9: Mineral Classes  Nesosilicate Sorosilicate Cyclosilicate Lec 9: Mineral Classes  Inosilicate Phyllosilicate Tectosilicate Lec 9: Mineral Classes  Si- O ratio = 1:4 Nesosilicate Isolated SiO4 tetrahedra Island silicate Ionic bonding Generally high specific gravity, hard, equidimensional habit, no cleavage Groups: phenacite, olivine, garnet, zircon, Al2SiO5, humite Lec 9: Mineral Classes  Garnet ((Ca, Mg, Fe, Mn)3(Al, Fe, Cr)2(SiO4)3) Zircon (ZrSiO4) Staurolite Olivine ((Mg, Fe)2 SiO4) Lec 9: Mineral Classes  Kyanite Al2SiO5 polymorph Andalusite Sillimanite Lec 9: Mineral Classes  Si- O ratio = 2:7 Sorosilicate 1 corner oxygen is shared Double island silicate Group: epidote Epidote Lec 9: Mineral Classes  Cyclosilicate Si- O ratio = 1:3 2 oxygens are shared Ring silicate Beryl (Be3Al2(Si6O18)) Tourmaline Lec 9: Mineral Classes Inosilicate Single/ double chain silicate Single chain Si- O ratio= 1:3 Double chain Si- O ratio= 4:11 Groups: pyroxene (single), amphibole (double) Generally green to black color, hard, vitreous Lec 9: Mineral Classes  Pyroxene Amphibole Lec 9: Mineral Classes Phyllosilicate Sheet silicate Si:O ratio= 2:5 Generally platy or flaky habit, 1 distinct cleavage, soft, low specific gravity, flexible, elastic Group: serpentine, clay mineral, mica, chlorite Lec 9: Mineral Classes Kaolinite Muscovite Talc Biotite Chlorite Lec 9: Mineral Classes  Serpentine Lec 9: Mineral Classes Tectosilicate Framework silicate Si- O ratio= 1:2 All oxygen are shared Stable, strongly bonded structure Groups: SiO2, feldspar (k- feldspar, plagioclase feldspar), feldspathoid, scapolite, zeolite Lec 9: Mineral Classes Quartz (SiO2) Lec 9: Mineral Classes  Orthoclase Lazurite (KAlSi3O8) Plagioclase feldspar ((Ca, Na) AlSi3O8) Lec 9: Mineral Classes