1. DSL #27 Identify each statement as either True or False. 1. 1. Fossil fuels formed millions of years ago from decayed plants and animals. 2. 2. Most places have winds strong enough to generate electricity. 3. 3. All minerals are solids, but not all solids are minerals. 4. 4. The word crystalline means that atoms are arranged in a repeating pattern.

3. What is a Mineral? Naturally-formed solid substance with a crystal structure Naturally-formed solid substance with a crystal structure Pyromorphite

4. What do all minerals have in common? Formed by natural processes. Are Inorganic Have a unique chemical composition (makeup) Have a crystalline shape- they have a definite volume and shape

5. Calcite Beryl (Emerald) How are Minerals classified or grouped? 90 elements occur naturally in the Earth’s crust. only 8 About 98% of the crust is made of only 8 of these elements Silicates The most common minerals belong to the Silicates Amethyst

6. Mineral Group CharacteristicsExamples Silicates Contain oxygen & silicon Contain oxygen & silicon The most abundant group of minerals The most abundant group of minerals Quartz Mica Feldspar MICA Quartz

7. Mineral Group CharacteristicsExamples Non- Silicates Make up only 5% of the Earth’s crust Make up only 5% of the Earth’s crust Include some of the most important minerals Include some of the most important minerals iron, copper, gold, silver, diamonds, rubies Silver Gold Ruby CopperDiamond Iron

8. How do minerals form? There are 2 ways that crystals form: The cooling of hot, liquid rock called magma causes compounds to combine Rapid Cooling = Small Crystals Slow Cooling = Large crystals The evaporation of water that has minerals dissolved in it

9. How do we identify Minerals? We look at Physical Properties These include: Color/Appearance Luster Streak Hardness Cleavage/Fracture

10. Physical Properties of Minerals (can be used to identify the mineral) Color Can be misleading Many minerals will have a similar appearance, but will have different impurities

11. Physical Properties of Minerals (can be used to identify the mineral) Luster Luster refers to the way a mineral reflects light Metallic Metallic = shiny like metal Non-metallic Non-metallic = dull, non-shiny surface Pyrite has a metallic luster Calcite has a non- metallic luster

12. Streak The color of the powdered form of the mineral The color of the streak can be different than the mineral Minerals must be softer than the streak plate Physical Properties of Minerals (can be used to identify the mineral)

13. Streak…can help identify quartz http://www.childrensmuseum.org/geomysteries/cube/b3.html

14. Physical Properties of Minerals (can be used to identify the mineral) Hardness How easily a mineral scratches materials Mohs Hardness Scale Scale from 1 (softest) to 10 (hardest) Test by seeing if the mineral can scratch different objects (like human fingernail, copper, penny, glass, steel file)

15. Physical Properties of Minerals (can be used to identify the mineral) Cleavage & Fracture The way the mineral breaks Cleavage—minerals break along smooth, flat surfaces and every fragment has the same general shape Fracture—minerals that break at random with rough or jagged edges

17. Cleavage or Fracture? 1. 4.3. 2.

18. Physical Properties of Minerals (can be used to identify the mineral)

19. Review 1. 1. What is a Mineral? 2. 2. Name 2 things that all minerals have in common? 3. 3. The mineral group, Silicates, is made up of what two elements? 4. 4. How are minerals identified? A naturally occurring solid with a crystal structure Inorganic, Crystalline Structure, Formed Naturally, Unique Chemical Composition Oxygen and Silicon Color, Luster, Streak, Hardness, Cleavage, Fracture