1. Understanding and identifying minerals

2. Minerals
Minerals are
Formed through natural processes
Inorganic (non-living)
Solid
Crystalline
Over 4000 types, but fewer than 100 common minerals

4. Natural Processes Natural processes that might cause minerals to form:
Heat from volcanic activity
Pressure from rock movement
Cooling from air or water
Addition of new material by wind or water

5. Inorganic Minerals are not created by living things
Organic matter can not be a mineral
Hair, dirt, leaves, nails/claws, oil, coal, anything made of proteins, carbohydrates, lipids, or nucleic acids
Shells of bivalves, diatoms, and other seashells are inorganic

6. Crystalline Solids Liquid water is not a mineral Lava is not a mineral
Solid ice is a mineral
Lava is not a mineral
Crystal: solid in which the atoms are arranged in a regular, repeating pattern
Each mineral has its own unique pattern

9. Crystalline Solids Minerals have definite structure and composition
Can be either elements or compounds
Minerals will always grow in the same pattern

10. Same Composition Different Structure

11. Native Carbon: Diamond

12. Native Carbon: Graphite

13. Amphibole (Hornblende)
Olivine
Pyroxenes (Augite)
Amphibole (Hornblende)
Micas
Feldspar, Quartz

14. Quartz: Most common mineral of the continents

15. Feldspar: Combines with quartz to make granite

16. Olivine: most common mineral in the earth’s mantle

17. Mineral Formation Minerals form by Cooling of magma or lava
Evaporation of water
Reactions within mineral rich water

18. Cooling of Magma Magma is molten rock Underground Magma
Molten = melted
Underground Magma
Above ground Lava
Most magma never becomes lava, it cools underground

19. Magma cooling underground

21. Cooling of Magma When magma cools, it solidifies
Cool  Solidify  Crystallize
Rocks: mixture of minerals
Magma can solidify in seconds or over millions of years

22. Cooling of Magma Quick cooling = small crystals
Atoms do not have time to arrange themselves
Slow cooling = large crystals
Atoms arrange and rearrange themselves until they are in the most stable positions

23. Small minerals
Feldspar in the cracks

24. Large minerals
Large feldspar

25. Very large minerals

26. Cooling of Magma Magma cools slowly; lava cools quickly
Lava traps more gas as it cools
Sometimes lava cools so quickly no crystalline structure can develop

27. Trapped Gas makes Pumice

28. Very quick cooling makes Obsidian(not a mineral)

29. Evaporation of Water
Water in nature always contains some amount of minerals  it is a solution
Hot water holds more minerals
Minerals can precipitate out of solution

30. Evaporation of Water
Precipitate: water evaporates but minerals are left behind
Halides (salts) are the most common example of this

31. Halite: Rock Salt

33. Reactions in Mineral Rich Water
Water deep below the surface can be very hot
Hot water = more minerals
As water moves up through cracks in rocks
Water cools  minerals are deposited
Hot water = minerals dissolve
Cold water = minerals precipitate

34. Reactions in Mineral Rich Water
When water deposits minerals into cracks in existing rock, veins are formed
When water deposits minerals into cavities in existing rocks, geodes are formed

35. Quartz Vein

36. Gold bearing vein in brown

37. Vein with a fault

40. Mining and Using Minerals
Almost everything you own or use is made from one of these two things
Plant and Animal remains: wood, cotton, food, oil, plastics
Minerals: metal, rock, cement, glass

41. Minerals Because minerals are made by natural processes, they must be
Found
Mined
Processed
Used/Disposed of
There are economic and environmental concerns in each of these steps

42. Finding Minerals
Minerals (especially useful ones) are generally found underground
Geologist find mineral deposits by
Studying local rocks
Mapping the area
Taking rock samples

43. Finding Minerals Ore: mineral deposits that can be mined for a profit
Mining is very expensive so extensive research is done before it begins

44. Mining
Surface mining: mining operations that are exposed on the earth’s surface
Pit mining
Strip mining
Quarrying
Underground mining: mining operations that are accessed by underground tunnels

45. Copper Mine: note the green water

46. Pit Mine

47. Coal Mine: note the depth and layering

48. Coal Mine

49. Quarry: note the size of the blocks

50. Abandoned quarries often become lakes

51. Underground Mining Accessed by tunnel
Much more expensive and dangerous than surface mining
Water, fresh air, cave-ins, movement of ore all take much more effort

53. Underground Mines

54. Economic and Environmental Concerns
Mining and ore handling provide many people with jobs
Almost every product we use requires mined material
Mines can be very bad for the local environment

55. Environmental Concerns
Mines affect the environment by
Removing soil and biodiversity
Deforestation
Changing courses of flowing water
Altering local topography
Releasing heavy metals and volatile chemicals

56. Sinkholes

57. West Virginian Mountain Removal

58. Seams of coal and a stream that is being filled with debris

59. Dangers of changing water flow

60. Processing Metals Metals are taken from rocks
Ores require a lot of processing to get usable metal
Heap leaching: addition of chemicals to remove ore
Flotation: attaches compound that floats minerals out of solution
Smelting: super-heating rock causing it to celebrate into layers
Recycling metals is important

61. Cassiterite: Tin Ore

62. Hematite: Iron Ore

63. Bauxite: aluminum ore

64. Processing Gemstones
Gem (gemstone): valuable rocks used in jewelry or industry