1. Geology Mineral (definition) 1. naturally occurring, 2. inorganic solid 3. with a specific chemical composition 4. a definite crystalline structure  Minerals can form from the cooling of magma which is the molten material found beneath Earth’s surface as magma rises closer to the surface the molten compounds no longer move freely and they begin to interact chemically to form minerals

2. Geology  Minerals form by combining elements together to create compounds. Each compound is unique and has specific properties that separate it from other compounds  Minerals are like rocks because all rocks are made of minerals

3. Mineral Properties  Streak is easily determined by rubbing the mineral across an unglazed porcelain plate

4. Mineral Properties  Streak is used to distinguish pyrite from gold

5. Mineral Properties  Luster is the way a mineral reflects light from its surface and is caused by differences in mineral chemical compositions

6. Mineral Properties  Either metallic or nonmetallic (dull, pearly, waxy, silky)

7. Mineral Properties  Texture describes how a mineral feels to the touch  Rough, smooth, ragged, greasy, soapy, glassy

8. Mineral Properties  Hardness is a measure of how easily a mineral can be scratched and is determined by the arrangement of it’s atoms.

9. Mineral Properties  The Mohs hardness scale is used to compare a sample to the hardness of ten known minerals

10. Mineral Properties  Cleavage determines whether a mineral will split easily and evenly along one or more flat planes

11. Mineral Properties  Mica has perfect cleavage in one direction  Halite has cubic cleavage (3 planes)

12. Mineral Properties  Fracture means the mineral is tightly bonded and breaks with rough or jagged edges  Quartz has fracture

13. Mineral Properties  Specific Gravity compares the weight of the mineral to an equal volume of water at 4 degrees C

14. Mineral Properties  Special Properties such as light reflection and reactions to acids are also useful tools

15. Mineral Properties  Calcite fizzles when in contact with HCl

16. Mineral Properties  Calcite also can cause double images

17. Mineral Properties  Magnetite will attract iron

18. Mineral Properties  Sulfur produces a rotten egg odor

19. Geology  Small crystals means the magma cooled rapidly  Large crystals means the magma cooled more slowly

20. Geology  Silicates are the most abundant group (96%) containing the two most abundant elements in the crust Silicon (Si) and Oxygen (O)

21. Geology  Quartz and Feldspar are the most abundant minerals found in Earth’s crust

22. Geology  Carbonates are minerals composed of one or more metallic elements with the carbonate compound CO3 ( 1 atom of carbon and 3 atoms off oxygen)

23. Geology  Carbonates are the primary minerals in rocks such as limestone, coquina, and marble LimestoneCoquinaMarble

24. Uses for Earth Materials  Nearly every single thing we use today comes from Earth directly or indirectly. The following is a list of minerals and ores

25. Uses for Earth Materials  Name of mineral/oreUse(s) Quartz (mineral)Glass, watches

26. Uses for Earth Materials Feldspar (mineral)Toothpaste

27. Uses for Earth Materials  Calcite (mineral)Neutralizing acids

28. Uses for Earth Materials Mica (mineral) Lampshades, insulation, makeup

29. Uses for Earth Materials Pyrite (ore)Iron

30. Uses for Earth Materials  Talc Baby powder

31. Uses for Earth Materials  Bauxite Aluminum

32. Virginia’s Important Resources  CoalEnergy

33. Virginia’s Important Resources  Gravel/stone (all) Road Construction

34. Virginia’s Important Resources  Limestone Concrete

35. Virginia’s Important Resources  Granite Building materials

36. Virginia’s Important Resources  silica electronics

37. Virginia’s Important Resources  zirconium & titanium advanced metallurgy

38. What are Rocks?  A rock is a naturally occurring solid mixture of one or more minerals, or organic matter  Rocks are classified by how they are formed, their composition, and texture  Rocks change over time through the rock cycle

39. Igneous Rocks  Igneous rock begins as magma.  Magma can form: When rock is heated When pressure is released When rock changes composition  Magma freezes between 700 °C and 1,250 °C  Magma is a mixture of many minerals http://www.fi.edu/fellows/payton/rocks/create/igneous.htm

40. Igneous Rocks  Felsic: light colored rocks that are rich in elements such as aluminum, potassium, silicon, and sodium  Mafic: dark colored rocks that are rich in calcium, iron, and magnesium, poor in silicon  Coarse-grained: takes longer to cool, giving mineral crystals more time to grow  Fine-grained: cools quickly with little to no crystals

41. Igneous Rocks Felsic Mafic Coarse-GrainedFine-Grained

42. Igneous Rocks  Intrusive Igneous Rocks: magma pushes into surrounding rock below the Earth’s surface  Extrusive Rocks: forms when magma erupts onto the Earth’s surface (lava), cools quickly with very small or no crystals formed http://www.windows.ucar.edu/tour/link=/earth/geology/ig_intrusive.html&edu=high&fr=t

43. Igneous Rocks Obsidian What is Obsidian? Obsidian is a dark-colored volcanic glass that forms from the very rapid cooling of molten rock material. It cools so rapidly that crystals do not form.

44. Sedimentary Rocks http://www.fi.edu/fellows/payton/rocks/create/sediment.htm  Sedimentary rock is formed by erosion  Sediments are moved from one place to another  Sediments are deposited in layers, with the older ones on the bottom  The layers become compacted and cemented together

45. Sedimentary Rock  Sedimentary Rocks are formed at or near the Earth’s surface  No heat and pressure involved  Strata – layers of rock  Stratification – the process in which sedimentary rocks are arranged in layers

46. Sedimentary Rock Clastic – made of fragments of rock cemented together with calcite or quartz

47. Sedimentary Rock Chemical sedimentary – minerals crystallize out of solution to become rock Rock SaltRock Salt is a chemical sedimentary rock that forms from the evaporation of ocean or saline lake waters. It is also known by the mineral name "halite". It is rarely found at Earth's surface, except in areas of very arid climate. It is often mined for use in the chemical industry or for use as a winter highway treatment. Some halite is processed for use as a seasoning for food. The specimen shown above is about two inches (five centimeters) across.

48. Sedimentary Rock Organic sedimentary – remains of plants and animals

49. Sedimentary Rock Organic sedimentary – remains of plants and animals

50. Metamorphic Rock http://www.fi.edu/fellows/payton/rocks/create/metamorph.htm  Meaning to change shape  Changes with temperature and pressure, but remains solid  Usually takes place deep in the Earth

51. Metamorphic Rocks  Contact Metamorphism – heated by nearby magma  Increased temperature changes the composition of the rock, minerals are changed into new minerals http://www.windows.ucar.edu/tour/link=/earth/geology/meta_contact.html&edu=hhttp://www.windows.ucar.edu/tour/link=/earth/geology/meta_contact.html&edu=h igh&fr=t

52. Metamorphic Rocks  Regional Metamorphism – pressure builds up in rocks that is deep within the Earth  Large pieces of the Earth’s crust collide and the rock is deformed and chemically changed by heat and pressure http://www.windows.ucar.edu/tour/link=/earth/geology/meta_regional.html&edu=high&fr=t

53. Metamorphic Rock  Foliated - contain aligned grains of flat minerals

54. Metamorphic Rock  Non-Foliated – mineral grains are not arranged in plains or bands

55. Metamorphic Rock  Determine if the following rock samples are foliated or non-foliated: Amphibolite Quartzite Phyllite