1. Ch 5- Minerals

2. Minerals Ch 5, p. 103 QOD- What is a mineral?

3.  Question set- #1-10 today. Show me when you finish 1-10 and then keep in notebook.  REMEMBER: LAB TOMORROW! –Missing contracts –Shoes & Lab Safety Rules

4. Sep 14  QOD- What are the seven physical properties used to identify minerals? 1.Review of Identifying Metals Lab 2.Video Clip- Minerals 3.Notes & Questions- ch 5 minerals 4.Keep the questions in your notebook 5.Test 4 – 5 Wednesday

6. Sep23 Earth Systems  Test- chapters 4 & 5 is Thursday!  Today- –Ch 5 notes  Tomorrow- –Last day to turn in mineral projects  Wednesday: Crystal Growing-! –Bring 1 pound (2 cups) sugar –Wear close toed shoes  Thursday- test ch 4-5

7. Is it a Mineral?  Is it inorganic?  Does it occur naturally?  Is it a crystalline solid?  Consistent chemical composition?  Must answer yes to all 4 questions for it to be a mineral

8. 10 Most common minerals  Quartz  Calcite  Orthoclase  Dolomite  Plagioclase  Halite  Muscovite  Gypsum  Biotite  Ferromagnesian minerals  These make up 90% of Earth’s mass

9. Mineral Groups  Silicates –96% of Earth’s crust –Contains Si (silicon) and O(oxygen) quartz –Can have other elements also –Feldspar –  Orthoclase if K (potassium),  Plagioclase if Na (sodium) or Ca (calcium) –Ferromagnesian minerals – rich in Fe (iron)

10. Orthoclase - LorenzenitePlagioclase - Albite Ferromagnesian - Olivine

11. Mineral GroupsMineral Groups  Nonsilicate Minerals –Do not contain Si and O  Can contain one or the other, but not both –Six groups  Carbonates  Native elements  Halides  Oxides  Sulfates  Sulfides

12. Carbonate - Calcite Halide - Halite Native Elements - Gold Oxides - Hematite Sulfates - Gypsum Sulfides - Galena

13. Crystalline Structure  Crystal – atoms, ions, or molecules are arranged in a regular, repeating pattern  Silicate crystal structure –Silicon – oxygen tetrahedron –1 Si with 4 O’s around it (illustrated in the book) –Basic building block of silicates –Can be connected 6 different ways

14. Silicate Tetrahedron

15. Crystalline Structure  Nonsilicate crystals –Diverse chemical composition leads to variety of crystal structures –Cubes, hexagonal prisms… –Crystal structure influences physical properties  Native elements are dense due to compact crystal structure

16. Physical Properties of Minerals  Mineralogist –Examine, analyze, and classify minerals  Result from chemical composition and crystal structure  Can be useful in identifying minerals

17. Physical Properties 1)Color Not reliable for ID purposes (subjective)Not reliable for ID purposes (subjective) Small amount of impurities can affect colorSmall amount of impurities can affect color Weathered surfaces may hide colorWeathered surfaces may hide color Only look at fresh surfacesOnly look at fresh surfaces

18. Color

19. Physical Properties 2)Streak Color of mineral in powder formColor of mineral in powder form Streak plate – unglazed ceramic tileStreak plate – unglazed ceramic tile Streak color may differ from mineral colorStreak color may differ from mineral color Metallic minerals – darker streakMetallic minerals – darker streak Nonmetallic minerals – lighter streakNonmetallic minerals – lighter streak

20. Streak

21. Physical Properties 3)Luster  Light reflected from mineral’s surface  Metallic luster – shiny surface  Nonmetallic luster  Glassy  Waxy  Pearly  Brilliant  Dull / Earthy

22. Metallic Luster

23. Glassy Luster Quartz

24. Waxy Luster Variscite

25. Pearly Luster Talc

26. Brilliant Luster Diamond

27. Dull / Earthy Luster Psilomelane

28. Physical Properties 4)Cleavage / Fracture –Cleavage  Splitting along specific lines of weakness  Forms smooth, flat surfaces –Fracture  Break unevenly into pieces  Forms curved, irregular surfaces  Conchoidal fractures – curved surface

29. Cleavage - Calcite

30. Fracture Conchoidal

31. Fracture Irregular

32. Physical Properties 5)Hardness  Ability to resist scratching  Mohs Hardness Scale  Scale of 1 to 10  1 = Talc10 = Diamond  Glass is about a 5

33. Mohs Hardness Scale

34. Physical Properties 6)Crystal Shape –6 Basic shapes –Certain minerals always form crystals with the same shape 7)Density –Ratio of mass to volume –Can help identify minerals

35. Crystal Shapes

36. Physical Properties  Fluorescence and phosphorescence  Chatoyancy and asterism  Double refraction  Magnetism  Radioactivity

37. Diamond fluorescence with ultraviolet light Phosphorescence – over time on a watch face

38. ChatoyancyAsterism

39. Double Refraction

40. Crystal Growing Lab- Wedn.  Bring 1 pound (2 cups) sugar  Wear close toed shoes