1. Ch. 4: Minerals

2. Earth’s crust is composed of about 3000 minerals!

3. Minerals Help form rocks Shape earth’s surface Shape our civilization Mineral: naturally occurring inorganic solid with specific chemical composition and definite crystalline structure

4. Salt vs. Sugar

6. Crystal Solid in which atoms are arranged in repeating patterns

7. Identifying Minerals Color: least reliable Luster: the way it reflects light –Metallic, shiny or non-metallic, dull, or pearly.. Texture: how does it feel? –Smooth, soapy, rough, greasy

8. Streak: color of a mineral when it’s broken up and powdered –Very consistent, only useable on softer minerals Hardness: how easily it can be scratched –Friedrich Moh’s scale –Very reliable

9. http://geology.com/rocks/

10. Density –How tightly compacted a substance’s molecules are D = m/v –Less dense than liquid: floats –More dense than liquid: sinks

11. Special properties Calcite bends light, gives a double image Magnetite: a natural magnet

12. Mineral uses Ore: a mineral is an ore if it… –contains a useful substance AND –can be mined for a profit

13. Gem – valuable mineral prized for beauty and rarity

14. Find the answers in ch. 4 What mineral forms rubies and sapphires? What’s the difference between them? Which is more valuable – a diamond or emerald? Why?

15. Matter: anything that has volume and mass –Made of elements Elements: substance that connot be broken down into smaller substances by physical or chemical means –Purely and completely ______________

16. Elements 92 naturally occuring elements on earth or in stars Hydrogen and Helium are the most abundant elements in the universe! Why?

18. Elements that are also minerals: Copper Silver Sulfur Most minerals are compounds

19. In Earth’s crust… Silicon and oxygen are the most abundant

20. In the atmosphere: 78% nitrogen 21% oxygen 1% ozone, water vapor

21. In the oceans: What do you think? Sodium Chloride Hydrogen Oxygen Why? 97% of all water on earth is salt water!

22. Back to Earth’s crust… Continental crust: granite Oceanic crust: basalt –More dense