Minerals and Rocks PDF

 MINERALS I. A mineral is: 1. A naturally occurring, 2. Inorganic, (next silde) 3. Solid, (the slide after that) 4. That has a definite chemical composition, and 5. A definite crystal structure Graphite – pencil lead, batteries Sul...

 MINERALS I. A mineral is: 1. A naturally occurring, 2. Inorganic, (next silde) 3. Solid, (the slide after that) 4. That has a definite chemical composition, and 5. A definite crystal structure Graphite – pencil lead, batteries Sulfur – matches, fireworks Talc – Powder, ceramics  not minerals: cement, steel (man -made) 2. IN ORGAN IC - N O T COM POSED OF ORGAN IC M ATTER ; N O T FROM LIVIN G THIN GS OR THE R EM AIN S OF LIVIN G THIN GS.  Coal is NOT a mineral because it comes from plants  Amber is NOT a mineral because it comes from tree sap  Pearls is NOT a mineral because it comes from oysters  SOLIDS 3. Have a definite volume and a definite shape.  Stable and solid at room temperature  Mercury is not a mineral because it is liquid at room temperature  CHEMICAL COMPOSITION Silicate Minerals Non-silicate minerals a) silicon and oxygen b) DO NOT contain SiO 2 groupings; SiO 2 1) subdivided into several 1) combined with one or other classes more metals 2) Extremely rare  Talc- Mg 3 Si 4 O 10 (OH) 2  8% of the Earth's crust 2) Largest group of 3) Few are relatively minerals common 1) 90% of the earth's crust  calcite  NON-SILICATE SUBDIVISIONS a) Native Elements –elements found in nature in their mineral form.  gold (Au), sulfur (S), silver(Ag) b) Sulfides – minerals that contain sulfur ions.  Galena (PbS), Pyrite (FeS 2 ) d) Sulfates - minerals which include the sulfate ion (SO 4 2- ).  Gypsum (CaSO 4 ·2H 2 O)  NON-SILICATE SUBDIVISIONS d) Oxides - minerals that contain oxygen bonded with one or more metals  Hematite (Fe 2O 3), Magnetite (Fe 3O 4)  minerals containing (OH) are typically included in this class. (hydroxides) Portlandite ( Ca(OH) 2) e) Halides - minerals with that contain Fluorine, Chlorine, Bromine and Iodine ions.  Halite (NaCl), Fluorite (CaF 2)  NON-SILICATE SUBDIVISIONS f) Carbonates – minerals that contain a carbonate ion, CO 2− 3.  Calcite ( CaCO 3) , Dolomite ( CaMg(CO 3) 2)  Many more subdivisions; each with chemical similarities  CRYSTAL STRUCTURE 1. The internal structure or arrangement of atoms within a mineral  Halite (NaCl) 2. Atoms/molecules are arranged in repeating geometric patterns. 3. SIX BASIC CRYSTAL SYSTEMS a) Cubic - Galena, Halite, Pyrite b) Tetragonal – Chalcopyrite c) Hexagonal - Quartz, Calcite d) Orthorhombic - Olivine, Topaz  SIX BASIC CRYSTAL SYSTEMS e) Monoclinic – Mica, gypsum f) Triclinic – Feldspar, Turquoise  MINERAL FORMATION 4. Minerals form a) When lava or magma cools to solidification b) When water evaporates and leaves minerals remain c) When water is supersaturated with a mineral; minerals will settle out of the water and deposit as a precipitate.  IDENTIFYING MINERALS 1. Minerals can be identified by their physical and chemical characteristics. a) Physical Properties: Color Streak Luster Hardness Cleavage or Fracture Density b) Chemical Properties  Specific and unique for each mineral  Determined by chemical composition and structure  PHYSICAL PROPERTIES 2. Color: Not a reliable property; some minerals can be many different colors. a) Color may vary due to: 1) Natural coloring agents - impurities 2) Weathering; exposure to the environment b) Malachite-green c) Quartz-clear, purple, white, grey-brown… d) Sulfur-yellow e) Hematite-black, silver, reddish brown  PHYSICAL PROPERTIES 3. Streak: The color of the mineral in its powdered form. a)Determined by using a streak plate 1) Quartz: White/colorless 2) Hematite: reddish brown  PHYSICAL PROPERTIES 4. Luster: The way a mineral shines/reflects light from its surface. a) Metallic: reflects light like the surface of a polished metal 1) Galena, Pyrite, Graphite, Magnetite… b) Non Metallic: reflects light in more subtle ways 1) Pearly-Mica 2) Glassy-Quartz 3) Dull/Earthy-Bauxite 4) Waxy-Talc 5) Brilliant-Diamond  PHYSICAL PROPERTIES 5. Hardness: A c) When a mineral measure of how scratches a substance; easily a mineral can be scratched. it is harder than the substance a) Determined by a minerals internal structure. b) When a mineral is scratched by a substance; it is softer than the substance TESTING HARDNESS Mohs Hardness Scale Hardness Name of Mineral 1 Talc Common Objects 2 Gypsum 2.5 Fingernail 3 Calcite 3.5 Copper 4 Fluorite 4.5 Iron Nail 5 Apatite 6 Feldspar 5.5 Glass 7 Quartz 6.5 Steel File 8 Topaz 7 Streak Plate 9 Corundum 10 Diamond  PHYSICAL PROPERTIES 6. Cleavage: When a mineral splits/breaks along smooth flat surfaces a) Mica - One direction; sheet b) Galena – Three; cubic shape a) Determined by atomic structure of mineral 1) Cleavage is the way a mineral breaks 2) Crystal Shape is the way crystal grows  PHYSICAL PROPERTIES 7. Fracture: When a mineral breaks unevenly into curved or irregular pieces with a rough and jagged surfaces. a) Sulfur, bauxite, hematite, quartz  PHYSICAL PROPERTIES 8. Density or Heft: Minerals have different densities, and vary in weight given the same sample size.  How heavy the mineral feels in your hand  CHEMICAL PROPERTIES a) Effervescence 1) Calcite reacts with HCl; bubbles of CO 2 b) Oxidation: 1) Reaction between Iron (Fe) and oxygen (O 2 ). a. Iron (Fe) + oxygen = Rust Metal is weakened by change 2) Reaction between copper and air; creates a greenish coating a) Copper (Cu) + oxygen = copper oxide  metal is not weakened; pennies  SPECIAL PROPERTIES a) Lodestone-Magnetite; is naturally magnetic b) Iceland Spar-Calcite; produces double refraction c) Pitchblend; radioactive  WHAT WOULD IT FEEL LIKE TO BE A MINERAL BEING TESTED? In the area provided Provide a written response to the question above You may choose to write about two or more mineral tests Include an answer to the following By which mineral property would you want to be identified by? Why  Which property would you not want? Why  USES OF MINERALS 1. Ore - A mineral that contains metals and nonmetals that can be mined and removed in usable amounts; for a profit a) Metals- elements that have a shiny surfaces, are able to conduct heat and electricity, and are malleable. 1) Iron-Hematite/Magnetite 2) Aluminum-Bauxite 3) Copper-Chalcopyrite/Malachite 4) Gold-Gold  USES OF MINERALS b) Nonmetals- Elements that have dull surfaces and are poor conductors of heat and electricity and are brittle. 1) Halite(NaCl)- Salt 2) Gypsum-Drywall, chalk 3) Calcite-Cement 4) Kaolinite-Bricks  USES OF MINERALS 2. Alloy- A mixture of two or more metals or a mixture of metals and nonmetals a) Tin+Copper= Bronze b) Copper+Zinc= Brass c) Iron+Chromium+Limestone= Steel d) Lead+Tin= Pewter  USES OF MINERALS 3. Gems- Minerals that have desirable qualities; such as hardness, color, luster, clarity, durability, rarity… a) Precious Stones:  Diamond, Rubies, Sapphires, Emeralds b) Semi-Precious Stones:  Amethyst, Garnet, Topaz c) Gems that are not minerals  Pearls, Amber  ROCKS IN RELATION TO MINERALS 1. Many kinds of rocks are composed of minerals a) Granite; mica, feldspar and quartz 2. Monomineralic; rocks that are composed of only one mineral. a) Marble– Calcite 3. Polymineralic; rocks that are composed of two or more minerals a) Granite 4. There are almost 4,700 different minerals  Silicates make up 90% of the crust.  WHAT ARE ROCKS? are naturally formed, non- living mass of organic and inorganic earth material consisting of one or more minerals that are held together in a firm, solid mass CLASSIFICATION OF ROCKS II. Rocks are classified based on their method of formation/origin. A. 3 Rock Groups 1. Sedimentary 2. Igneous 3. Metamorphic  SEDIMENTARY ROCKS  formed from the compaction and cementing together of sediments (materials that settle out of air and water), broken pieces of rock life gravel, sand, silt or clay.  Common formation sites include river beds, lakes, deserts, coastal areas, marine environments, and glacial regions.  IGNEOUS ROCKS C. These rocks form from the cooling and solidification of molten rock material known as magma (when it is beneath the Earth's surface) or lava (when it erupts onto the surface). TYPES OF IGNEOUS ROCKS a) Extrusive/Volcanic: Forms from the fast cooling of lava on or near Earth’s surface. 1) Rapid cooling does NOT allow time for crystals to grow. 2) Rocks have small to no crystals; smooth/fine texture. TYPES OF IGNEOUS ROCKS b) Intrusive/Plutonic: Form from the slow cooling of magma within or beneath the Earth 1) Slow cooling allows time for large crystals to grow 2) Rocks have large crystals; coarse/rough texture ENVIRONMENT OF FORMATION Rate of Grain Size Texture Example cooling Very Non- Obsidian Glassy Extrusive Fast crystalline Pumice (Volcanic) Less than Basalt Fast Fine 1mm Rhyolite Intrusive (Plutonic) 1mm or Granite Slow Coarse larger Diorite  CRYSTAL SIZE VS. COOLING RATE 1) Location in Earth’s crust effects the cooling rate and crystal size No Crystals Very Fast Cooling Crystal Size Small Crystals Fast Cooling F S Rate of Cooling Large Crystals Slow Cooling  METAMORPHIC ROCKS These rocks form from the alteration of pre- existing rocks (igneous, sedimentary, or even other metamorphic rocks) through heat and pressure, or chemically active fluids. This process, known as metamorphism, leads to changes in mineral composition and texture.  METAMORPHISM  involves the alteration of the mineral composition and texture of a pre-existing rock (the parent rock) due to changes in temperature, pressure, or the presence of chemically active fluids. This process results in the formation of a metamorphic rock. Conditions that cause rocks to undergo metamorphism 1) Heat 2) Pressure 3) Chemical Activity  METAMORPHIC ROCKS Metamorphic Texture Rock Original Rock Slate Shale Sedimentary Foliated Un-foliated Schist Slate Metamorphic Gneiss Granite Igneous Marble Limestone Sedimentary Quartzite Sandstone Sedimentary Anthracite Coal Bituminous Coal Sedimentary  Process Description Sedimentation The process where layers of rock particles build up Compaction and The process where the layers of sediment are Cementation compressed and stuck together Heat and Pressure The process that can change sedimentary rock into metamorphic rock Melting The process which can form igneous rock, where solid rocks are turned to molten rock Uplift The process where rocks are pushed upwards by the pressure of rocks forming underneath Weathering The process by which large rocks are broken down into smaller parts Erosion, Transportation, and The processes by which rock particles are moved Deposition  FAMOUS ROCKS  White House; Sandstone  Grand Canyon; layers of sedimentary rocks  Pyramids; Limestone  Mount Rushmore; Granite  Great Wall of China; stone; brick, etc…  Stonehenge  V Rocks Sedimentary Igneous Metamorphic Clastic Organic Crystalline Intrusive Extrusive Foliated Unfoliated Sediment Bioclastic Chemical Plutonic Volcanic Conglomerate Pumice Bituminous Coal Limestone Granite Slate Marble Sandstone Obsidian Limestone Rock Salt Gabbro Schist Quartzite Siltstone Basalt Chalk Rock Gypsum Diorite Gneiss Anthracite Coal Shale Rhyolite