aluminum – airplane skins Minerals aluminum – airplane skins gold & silver – jewelry talc – baby powder graphite – pencil lead Updated 3/15/2009 Created by C. Ippolito March 2009

Minerals vs. Rocks Rock Mineral an mixture of minerals naturally occurring inorganic solid with definite chemical structure and unique physical properties natural inorganic solid definite composition orderly arrangement of atoms Updated 3/15/2009 Created by C. Ippolito March 2009

Chemistry Review Element Atom cannot be broken into simpler substances smallest part of element retaining properties Nucleus – dense central region protons - + charge, 1 amu mass neutrons – 0 charge, 1 amu mass Energy Levels – “clouds” electrons - - charge, 1/1837 amu Updated 3/15/2009 Created by C. Ippolito March 2009

Classify Elements Atomic Number Mass Number Isotope Atomic Mass # of protons Mass Number sum of protons & neutrons Isotope atoms of same element with different mass numbers differing numbers of neutrons Atomic Mass weighted average of masses of all isotopes of element Radioisotopes unstable due to weak nuclear forces break apart and decay Updated 3/15/2009 Created by C. Ippolito March 2009

Minerals as Compounds Compound atoms or two or more elements chemically combined Covalent Bonds nonmetals share electrons Ionic Bonds metal (loses) nonmetal (gains) – electron transfer Metallic Bond pure metals electrons freely move around positive centers “sea of electrons” Updated 3/15/2009 Created by C. Ippolito March 2009

Mineral Formation Magma Process Pressure Process particles move together and bond mass together as “grains” Pressure Process minerals break down then recombine in new ways Updated 3/15/2009 Created by C. Ippolito March 2009

Mineral Physical Properties Crystal Structure regular geometric solid with smooth face Color exotic changes with impurities (quartz) inherent consistent based on structure (sulfur, malachite) Updated 3/15/2009 Created by C. Ippolito March 2009

Streak Luster Hardness mineral color in powdered form quality of light reflected from surface Hardness resistance to abrasion or scratching Moh’s Scale 1 (softest) to 10 (hardest) Updated 3/15/2009 Created by C. Ippolito March 2009

Cleavage Fracture tendency to break on planes of “weak bonds” break irregularly Updated 3/15/2009 Created by C. Ippolito March 2009

Crystal Systems Cubic Orthorhombic Tetragonal 3 axes, equal length, 90° sylvite, halite Orthorhombic 3 axes, each different 90° topaz, sulfur Tetragonal 3 axes, two equal, 90° zircon, wulfenite Updated 3/15/2009 Created by C. Ippolito March 2009

Triclinic Hexagonal Monoclinic 3 axes, each different oblique angle kyanite, turquoise Hexagonal 3 axes, equal length, 60° on four axes, third vertical emerald Monoclinic 3 axes, each different, two 90°, third oblique gypsum, mica Updated 3/15/2009 Created by C. Ippolito March 2009

Silicate Minerals formed from silicon and oxygen silicate tetrahedron Updated 3/15/2009 Created by C. Ippolito March 2009

Silicate Classes Olivine Pyroxine Amphibole Mica Feldspar no cleavage, single Pyroxine two perfect, chain Amphibole 1 perfect, 1 imperfect 2 chains 60° & 120° Mica perfect in 1 direction, sheet Feldspar 2 good, 90° Updated 3/15/2009 Created by C. Ippolito March 2009

Mineral Groups Silicates Carbonates Oxides Sulfides Sulfates Halides 90% of minerals quartz, feldspar, pyroxene, mica, amphibole, kaolinite Carbonates calcite CaCO3, dolomite CaMg(CO3)2, malachite Cu2(OH)2CO3 Oxides hematite Fe2O3, magnetite Fe3O4, corundum Al2O3 Sulfides galena PbS, sphalerite ZnS, pyrite FeS, chalcopyrite CuFeS2 Sulfates gypsum CaSO4•2H2O Halides halite NaCl, fluorite CaF2 Updated 3/15/2009 Created by C. Ippolito March 2009

Quartz luster color fracture hardness use glassy, greasy pure – white/colorless rose, amethyst, smoky fracture conchoidal/irregular hardness 7 use component of granite semiprecious stones, prisms, heat lamps return Updated 3/15/2009 Created by C. Ippolito March 2009

Feldspar luster color cleavage hardness use pearly K – pink/salmon - orthoclase Na – white/gray – plagioclase albite, labradorite cleavage 2 directions less than 90° hardness 6 use glass & ceramics manufacture return Updated 3/15/2009 Created by C. Ippolito March 2009

Pyroxene luster color cleavage hardness streak use glassy/metallic black cleavage 2 planes almost 90° hardness 5-6 streak white/light green/brown use paints, plastics, replacement for asbestos return Updated 3/15/2009 Created by C. Ippolito March 2009

Mica luster color cleavage hardness streak use vitreous, pearly, metallic color biotite – black muscovite – white cleavage 1 plane hardness 2.5 streak white use insulators, paints, plastics, rubber, roofing return Updated 3/15/2009 Created by C. Ippolito March 2009

Amphibole luster color cleavage hardness streak use shiny horneblend – green/brown cleavage 2 planes, oblique angle hardness 5-6 streak brown to gray use mineral specimen return Updated 3/15/2009 Created by C. Ippolito March 2009

Kaolinite luster color cleavage hardness streak use earthy (dull) white cleavage 1 plane, perfect hardness 2 streak use china clay return Updated 3/15/2009 Created by C. Ippolito March 2009

Calcite luster color cleavage hardness streak use vitreous (glassy) Colorless, White, Pink, Yellow, Brown. cleavage perfect , rhombohedral hardness 2 streak white use limestone, marble return Updated 3/15/2009 Created by C. Ippolito March 2009

Dolomite luster color cleavage hardness streak use vitreous (glassy) White, Gray, Reddish white, Brownish white, Gray cleavage perfect , rhombohedral hardness 3.5-4 streak white use limestone, marble return Updated 3/15/2009 Created by C. Ippolito March 2009

Hematite luster color cleavage hardness streak metallic Reddish gray, Black, Blackish red cleavage none hardness 5-6 streak reddish brown return Updated 3/15/2009 Created by C. Ippolito March 2009

Magnetite luster color cleavage hardness streak metallic black none 5.5-6 streak reddish brown return Updated 3/15/2009 Created by C. Ippolito March 2009

Galena luster color cleavage hardness streak metallic gray perfect 2.5 grayish black return Updated 3/15/2009 Created by C. Ippolito March 2009

Pyrite luster color cleavage hardness streak use metallic Pale brass yellow cleavage pure hardness 6 streak greenish black use return Updated 3/15/2009 Created by C. Ippolito March 2009