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MINERALS

MINERALS. http://sciencespot.net/Media/mghtmincl.gif. Mineral Composition. •     Minerals are made of elements Elements are made up of atoms Atoms are the basic building blocks of all matter. They are invisible Atoms are organized on the Periodic Table of Elements. Atoms.

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MINERALS

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  1. MINERALS http://sciencespot.net/Media/mghtmincl.gif

  2. Mineral Composition •     Minerals are made of elements • Elements are made up of atoms • Atoms are the basic building blocks of all matter. They are invisible • Atoms are organized on the Periodic Table of Elements

  3. Atoms • They contain 3 parts… • Protons • Found in the nucleus • Positive charge • Neutrons • Found in the nucleus • Charge of 0 • Electrons • Orbits the nucleus • Negative charge

  4. Element • A substance in which all of the atoms are the same. • The major elements in Earth’s crust are • O - Oxygen • Si -Silicon • Al -Aluminum • Fe -Iron • Acompound is a substance in which there are 2 or more types of atoms.

  5. Periodic TableWhere elements are arranged • Atomic number • Number of protons • Element symbol • Atomic mass • Mass of protons + Mass of neutrons

  6. Symbols to know •       Aluminum – Al •       Calcium – Ca •       Carbon – C •       Chlorine – Cl •       Copper – Cu •       Helium – He •       Hydrogen – H •       Iron – Fe •       Lead – Pb •       Gold- Au •       Argon- Ar •       Magnesium – Mg •       Mercury - Hg •       Nitrogen – N •       Oxygen – O •       Potassium – K •       Silicon – Si •      Sodium – Na •       Sulfur – S •       Uranium – U • Silver- Ag • Phosphorus-P

  7. Periodic Table Information • Each element is made of all the same kind of atom • Elements can combine together to form compounds which have a definite chemical formula • Which elements combine depend on the electron configuration. • Substances can combine to form mixtures.

  8. Connection to Minerals • Minerals are made up of a single element or a compound. • Since compounds are combinations of elements, it is important to know how and why elements combine. • The properties of minerals are due to the internal structure of the atoms.  • Otherwise known as their crystal arrangement. • 6 crystal structures

  9. Is it possible for two different minerals to have the same chemical composition? • YES! Both diamond and graphite are made of carbon. The difference between these two minerals is the way in which the carbon atoms are arranged.

  10. Silicon-OxygenTetrahedron(SiO4) Isolated Tetrahedrons (Olivine)

  11. Tetrahedron Arrangement Single-Chain Double-Chain Sheet Pyroxene Amphibole Mica

  12. Characteristics of a Mineral • Naturally occurring • Inorganic (generally) • Solid substance • Definite chemical composition • Orderly crystalline structure pyrite http://www.windows2universe.org/earth/geology/images/pyrite_sm.jpg

  13. What are minerals? • Minerals are aggregates of rocks. • This means many different minerals make up rocks. • Some major rock forming minerals • Quartz • Feldspar • Calcite • Mica

  14. Mineral Formation • Cooling of magma- The slower the rate of cooling the larger the crystal. • Precipitation - evaporation of water leaves the mineral behind- precipitate 3. Pressure and Temperature - causes atoms to rearrange and form new minerals 4. Hydrothermal solutions -mineral formation from hot mixtures.

  15. Mineral Groups • 4000 minerals make up the Earth’s crust, but 98% of the crust is made up of only 8 elements. • Most rock forming minerals are silicates. • Silicates are minerals that contain silicon and oxygenand usually one or two more elements. • Other minerals are classified by their composition. Examples include carbonates, oxides, and halides.

  16. Silicates contain silicon and oxygen, the two most common elements in Earth’s crust - make up 90% of all minerals -common silicates: feldspar, quartz http://volcano.oregonstate.edu/vwdocs/vwlessons/lessons/Slideshow/Show1/k-spar11.jpg http://mineralminers.com/images/rock-crystal/quartz-crystals/quartz-crystal-clusters.jpg

  17. Non silicates • Non-silicates – -do not contain a combination of silicon & oxygen http://ms.yccd.edu/earth_science/PhysicalGeology/nonsilicates.jpg

  18. Carbonates • Composed of carbonate compound: CO3 • Examples: calcite and dolomite http://richardkruse.com/Misc_Photos/Minerals/Mineral_Calcite_RK2008.jpg http://portableplant.net/oreimages/dolomite.jpg

  19. Oxide Group • Composed of oxygen and a metal • Examples: hematite and magnetite http://www.mii.org/Minerals/minpics/Magnetite.jpg http://www.redorbit.com/media/uploads/2004/10/28_30e4ecba792d2b734beb4d32901c1f58.jpg

  20. Sulfates and Sulfides • Minerals that contain element sulfur • Sulfates: • Anhydrite • Gypsum • Sulfides • Galena • pyrite gypsum http://geology.com/minerals/photos/gypsum-159.jpg pyrite http://www.mineralminers.com/images/pyrite/mins/pytm174.jpg

  21. Halides • Contain a halogen • From Group 17 • Example: halite (NaCl)- tastes like salt!

  22. Native Elements • Minerals containing only one element or type of atom • Gold • Silver • Copper • Sulfur • carbon http://www.mii.org/Minerals/Minpics1/Gold%203.jpg http://www.mii.org/Minerals/Minpics1/Silver.jpg http://www.rocksforkids.com/images/copper%20straw.jpg

  23. Two Major Mineral Groups Silicates Non-silicates Carbonates Oxides Sulfates sulfides Halides Native Elements Contain silicon and oxygen; olivine, mica, feldspar, quartz Contain Sulfur; gypsum, galena, pyrite Contain a halogen – From Group 17; halite (NaCl) Contain only one type of atom or element; gold, silver, copper Contain O and one or more other elements, Usually a metal; hematite Contain C, O and one or more other metallic elements; calcite, dolomite

  24. MineralPhysical and Chemical Properties http://www.kgs.ku.edu/Extension/KGSrocks/jpegs/Displaycase2.jpg

  25. Properties of MineralsMineral Identification • Physical and Chemical • Nearly 4000 different minerals exist, but only 50 are common. These minerals are identified using 6 basic characteristics.

  26. Color The same mineral may exhibit many different colors Ex: Quartz rose/purple/smoky/clear NOT a good mineral identifier COLOR

  27. Hardness • The measure of resistance to abrasion. • Hardness is measured on a scale called Mohs Hardness scale. • Talc is the softest mineral. • Quartz is the hardest common mineral. • Diamond is the hardest mineral http://upload.wikimedia.org/wikipedia/commons/a/a5/QuartzUSGOV.jpg Quartz Diamond Talc

  28. Four common objects that are used to test hardness: your fingernail (hardness is approx. 2.5) a copper penny (hardness is approx. 3.0) a steel knife blade (hardness is approx. 5.5) glass (hardness is approx. 6.0) HARDNESS

  29. Hardness Test quartz scratching glass

  30. Streak • The color of the mineral in powder form. • This can be determined by using a streak plate. • Metallic minerals leave a dark streak. • The color of a powdered sample of a mineral – always the same!

  31. Luster • The appearance or quality of light reflected from a minerals surface. • The luster can be metallic or nonmetallic. • If a mineral is nonmetallic it can have vitreous, pearly, resinous or earthy luster.

  32. Metallic Lusterexample - galena

  33. Non-Metallic Lusterexample - gypsum

  34. Density (Specific Gravity) • All minerals have density (mass / volume), but some are very dense • Specific Gravity is the density of the mineral compared with density of water http://www.minerals.net/mineral/elements/gold/gold1.htm

  35. Cleavage Cleavage of BiotiteMica: one-directional • Tendency of mineral to cleave, or break, along flat, even surfaces, where bonding is weak. • Mica has excellent cleavage. • It breaks into thin sheets Rhombic Cleavage of Calcite: (3-directions) Cubic Cleavage of Halite: 3-directions

  36. Fracture • The mineral exhibits no cleavage. • Fracture is a type of break where uneven jagged surfaces are produced. • If a mineral breaks in smooth curved surfaces it has conchoidal fracture. • Examples = sulfur & pyrite fracture

  37. Unique properties of minerals • Effervescence • When dilute HCL acid is dropped on a mineral it begins to bubble. This identifies the presence of Calcium Carbonate. • Florescence • The mineral glows when you put it under UV light (blacklight) • Magnetism • The mineral exhibits magnetic properties. • Double Refraction • Mineral refracts light and gives “double refraction”

  38. Magnetic PropertiesExample = Magnetite Acid TestCalcite reacts with dilute hydrochloric acid Halite tastes like salt. Double Refractionexample = Calcite Graphite has a greasy feel. Sulfur – strong smell

  39. Why are minerals important? • Minerals make up rocks • Provide valuable resources - Economic and manufacturing resources • Key evidence that the Earth and dynamic and changing

  40. Ore • Ores are minerals that contain useful substances that can be mined for profit. • A common example is bauxite which is turned into aluminum. • Major ore minerals: • Pyrite • Magnetite • Hematite • Galena • Graphite • sulfur Iron Ore

  41. Uses of minerals • Aluminum--packaging, transport, building • Beryllium--gemstones, fluorescent lights • Copper--electric cables, wires, switches • Feldspar--glass and ceramics • Iron--buildings, automobiles, magnets • Calcite--toothpaste, construction • Gold is used for jewelry • Talc is used for baby powder • Quartz is used for glass • Limestone can be processed to make concrete • Gems are brighter and more colorful than common minerals. This makes them rare and highly prized. http://buygoldinternational.com/img/upload/gold-jewelry.jpg

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