Rocks and Minerals

1. Rocks and Minerals Chapters 10 & 11 Rocks and Minerals • Science, 8th Grade

2. Rocks • Earth’s crust is made of rock. • Rocks are mixtures of minerals and sometimes other materials. background image source: http://veimages.gsfc.nasa.gov/7100/world.topo.bathy.200401.3x5400x2700.jpg Rocks and Minerals • Science, 8th Grade

3. Studying Rocks • When studying a rock sample, geologists observe the rock’s: • Color • click here for a rock color chart • Texture • Chemical Composition Rocks and Minerals • Science, 8th Grade

4. Color Chart Quiz image source: http://geology.about.com/library/bl/images/blgneiss.htm Click the color on the color chart that best identifies the color of the rock above. Rocks and Minerals • Science, 8th Grade

5. That is not correct… • Please click on the “Back” button and try again. Back Rocks and Minerals • Science, 8th Grade

6. Excellent! • You have correctly identified the rock on the color chart. Click on the “Next” button to continue. Next Rocks and Minerals • Science, 8th Grade

7. Texture • Most rocks are made up of grains, particles or minerals, or other rocks. • Texture is the look that results from: • Size • Shape • Pattern of rock’s grains Rocks and Minerals • Science, 8th Grade

8. Grains • Coarse-grained: large/easy to see • Fine-grained: small, even microscopic • Click here for rock identification tables that include information on grain size. Obsidian – A Fine-grained Rock image source: http://geology.about.com/library/bl/images/blobsidian.htm Sandstone – A Coarse-grained Rock image source: http://geology.about.com/library/bl/images/blsandstone.htm Rocks and Minerals • Science, 8th Grade

9. Grain Pattern • Grains in rock often form a pattern. • Flat layers (strata) • Wavy, swirling patterns • Rows of beads • Random or no pattern Example Example Example Example Rocks and Minerals • Science, 8th Grade

10. Flat Layers (strata) Back Rocks and Minerals • Science, 8th Grade

11. Wavy, Swirling Patterns Back Rocks and Minerals • Science, 8th Grade

12. Rows of Beads Back Rocks and Minerals • Science, 8th Grade

13. Random or No Pattern Back Rocks and Minerals • Science, 8th Grade

14. Quick Forming Rocks • Some rocks have no grain because they cooled too quickly when they formed. Rocks and Minerals • Science, 8th Grade

15. Rock Groups • There are three groups of rocks: • Igneous • Metamorphic • Sedimentary • Click on the links above to find the definition of each group of rock. Once you have reviewed these definitions online, click on the arrow to continue. Rocks and Minerals • Science, 8th Grade

16. Igneous Rocks • Formed from the cooling of molten, or melted, rock Pumice Granite Basalt Rocks and Minerals • Science, 8th Grade

17. Metamorphic Rocks • Formed when existing rock is changed by heat, pressure, or chemical reactions Gneiss Schist Phyllite Rocks and Minerals • Science, 8th Grade

18. Sedimentary Rocks • Formed when particles of other rocks, plants, or animals are cemented together Sandstone Breccia Siltstone Rocks and Minerals • Science, 8th Grade

19. The Rock Cycle Click here for another illustration of the rock cycle. Rocks and Minerals • Science, 8th Grade

20. Online Rock Cycle Activities • The Rock Cycle • Click on the image below to access online resources and activities. Rocks and Minerals • Science, 8th Grade

21. Minerals Rocks and Minerals • Science, 8th Grade

22. Minerals • A mineral: • Occurs naturally • Is inorganic • Is Solid • Has a crystal structure • Has a definite chemical composition Rocks and Minerals • Science, 8th Grade

23. Minerals • There are three thousand (3000) minerals. • One hundred (100) minerals are common. • Twenty (20) minerals make up most of the rocks of Earth’s crust (rock-forming minerals). Rocks and Minerals • Science, 8th Grade

24. Mineral Formation • Minerals form through: • Crystallization of melted materials. • Crystallization of materials dissolved in water. Rocks and Minerals • Science, 8th Grade

25. Crystals • Repeating patterns of a mineral’s particles that form a solid. • Click here for a crystal experiment from National Geographic. Rocks and Minerals • Science, 8th Grade

26. Mineral Composition • All minerals contain certain elements in definite amounts. • Most minerals are compounds (two or more elements). • Silver and gold are considered minerals. Rocks and Minerals • Science, 8th Grade

27. Mohs Hardness Scale • The Mohs Hardness Scale ranks ten minerals from softest to hardest. source: http://www.amfed.org/t_mohs.htm Rocks and Minerals • Science, 8th Grade

28. Ranking Minerals • Minerals are ranked according to: • Click on the word below for more information. • Color • Streak • Luster • Density • Cleavage • Fracture Rocks and Minerals • Science, 8th Grade

29. Color Back Rocks and Minerals • Science, 8th Grade

30. Streak • Streak is the color of a mineral’s powder. Back Rocks and Minerals • Science, 8th Grade

31. Luster • Luster is how shiny a mineral is. Back Rocks and Minerals • Science, 8th Grade

32. Density • Density is mass per unit volume (specific gravity). Back Rocks and Minerals • Science, 8th Grade

33. Cleavage is the breaking of a mineral along a regular line. Cleavage Back Rocks and Minerals • Science, 8th Grade

34. Fracture • Fracture is the irregular breaking of a mineral. Back Rocks and Minerals • Science, 8th Grade

35. Fluorescence • Fluorescence refers to minerals that glow under ultraviolet light. Rocks and Minerals • Science, 8th Grade

36. Magnetism • Magnetism occurs naturally in some minerals, such as magnetite. Rocks and Minerals • Science, 8th Grade

37. The End • Click here for another online resource about rocks and minerals. • Click the arrow below to return to the beginning of this presentation. Rocks and Minerals • Science, 8th Grade