1. Minerals

2. What are minerals composed of? Elements and Compounds What is an element? Matter composed of only one kind of atom kind of atom

3. What does an atom look like? Here is an example of an atom of the element Boron. Boron has a symbol of B on the periodic table and has the atomic number 5. Its mass number is 11. Here is an example of an atom of the element Boron. Boron has a symbol of B on the periodic table and has the atomic number 5. Its mass number is 11. Nucleus + o o + o o o + + o + 5 B Boron 10.81 _ _ _ _ _

4. Protons, Neutrons, Electrons Proton – subatomic particle in the nucleus with a positive charge Neutron – subatomic particle in the nucleus with no charge Electron – subatomic particle that orbits the nucleus with a negative charge

5. Atomic Number – number of protons in the nucleus of an atom Mass Number – number of protons AND neutrons in the nucleus of an atom (protons + neutrons = mass number) (protons + neutrons = mass number) 14 Si Silicon 28.086

6. Combinations of Atoms Molecule – formed when two or more atoms combine Molecules can be formed from the SAME atoms Example: O 2 Molecules can also be formed from the combinations of DIFFERENT atoms (these are also called COMPOUNDS) Example: H 2 O

7. What is the difference between an element, a molecule, and a compound? Here are some examples of each: Elements Pb C Molecules O 3 N 2 Compounds NaCl CaCO 3

8. The 8 most abundant elements in the Earth’s crust are: 1. Oxygen 2. Silicon 3. Aluminum 4. Iron 5. Calcium 6. Sodium 7. Potassium 8. Magnesium

9. Examples of Native Minerals (minerals composed of only one element) Sulfur (S) Gold (Au) Silver (Ag) Copper (Cu)

10. Minerals

11. What defines a mineral? Mineral – a naturally occurring inorganic solid with a definite structure and chemical composition

12. All minerals share the following 5 characteristics: 1. all are formed by natural processes (not man-made) 2. all are inorganic (non-living) 3. all are solids at room temperature 4. all have a definite chemical composition (made of elements/compounds) 5. all have atoms arranged in a repeating pattern (crystalline)

13. The 3 ways minerals can form: 1. Cooling of hot molten rock (magma/lava) 2. Chemical reaction through heat and pressure 3. Evaporation (liquid in which minerals are dissolved evaporates and the atoms are left behind to form crystals)

14. Mineral Groups Minerals are grouped based on composition (chemical make-up) 90% of all minerals are in the Silicate group Silicates are minerals that contain silicon and oxygen (basic building block of a silicate is the silica tetrahedron – SiO 4 )

15. QUARTZ – The #1 Silicate Quartz is the most abundant mineral in the world and is a silicate. It is the most abundant mineral because it is composed of the two most abundant elements in the world – oxygen and silicon

16. Other Mineral Groups Some other examples of mineral groups are the carbonates, phosphates, oxides, and sulfides. There are many other groups, these are just some other examples.

17. Oxides (O 2 + metal) Magnetite Hematite

18. Phosphates ( CaP + metal) Amazonite

19. Sulfides (S + metal) Pyrite

20. The Carbonates (CO 3 + metal) Calcite Azurite Malachite

21. Mineral Identification Properties

22. 1. Hardness – a measure of how easily a mineral can be scratched We use Moh’s Hardness Scale to help determine a mineral’s hardness Moh’s Hardness Scale (1 softest → 10 hardest)

23. 2. Luster – how light is reflected from a mineral’s surface Metallic – shiny like a metal Non-metallic – dull, pearly, glassy, brilliant

24. 3. Color – the least reliable mineral property Easily identified but the least reliable because many minerals can be found in various colors All of these minerals are Quartz

25. 4.Streak – color of a mineral when it is broken up and in powder form (streak plates have a hardness of 7)

26. 5. Cleavage and Fracture – the way in which a mineral breaks Cleavage – breaks along smooth flat surfaces (mica) Fracture – breaks with rough or jagged edges (quartz)

27. Some other properties are: Magnetism (Magnetite) Fluorescence (Fluorite and Calcite)

28. More Properties: Smell (Sulfur – rotten eggs) Taste (Halite – Salty) Heft Crystal Shape

29. More Properties: Specific Gravity – density of a mineral compared to the density of water

30. Properties specific to the mineral Calcite Calcite and HCL (a chemical reaction takes place takes place releasing CO 2 ) releasing CO 2 )

31. Double Refraction (light bending of calcite)

32. Mineral Uses

33. Gems – minerals that are highly prized because they are rare and beautiful after being polished Two types of gems: 1.precious – diamond, ruby, emerald 2.semiprecious – amethyst (purple quartz), citron, hematite

34. Two Types of Gems Semi-Precious Precious

35. Ores – a valuable mineral, usually a metallic element that can be separated from the rock in which it was found must be useful and profitable after mining costs the remainder of the leftover rock is known as the gangue

36. Ores Some examples are: Some examples are: Mineral → Useful Metallic Substance Bauxite → Aluminum Hematite → Iron Galena → Lead Chalcopyrite → Copper

37. How do geologist find these useful minerals? They prospect for ore deposits. A prospector is a scientist that looks for useful minerals. What do they look for? –Type of rock –Plant growth –Test streams for presence of minerals

38. Once a mineral is found how is it extracted from the Earth? Geologist use different mining techniques

39. Types of Mines Strip Mine Geologists use earth-moving equipment scrapes away soil to expose ore

40. Types of Mines Open Pit Mine Dig tremendous pit to remove ore deposits

41. Types of Mines Shaft Mine Used for ore deposits that occur in veins. Often a network of tunnels that extend into the ground.

42. Smelting Ore must be processed before the metals they contain can be used Ore is melted to separate useful metal from other elements

43. Environmental Impact of Mining Waste materials from mining can pollute rivers and lakes Mining destroys habitat Strip mining and open pit mining scars the land Environmental Protection Agency (EPA) require mine operations do as little damage as possible. Today, laws require Reclamation of land to take place after mining.

44. Reclamation Restoring land after mining Before Reclamation After Reclamation