2. CHAPTER 3 MINERALS http://www.gimizu.de/sgmcol/ http://www.gimizu.de/sgmcol/ 3.1 Minerals - Over 4,000 on Earth - 5 common characteristics 1. Formed naturally 2. Solid 3. Unique chemical compound 4. Form crystal pattern 5. Inorganic (No Carbon)

3. 3 Ways Minerals Form 1. Cooling of magma 2. Minerals dissolved in liquid 3. Precipitate out of solution http://www.mountaininterval.org/photos/images/b19-roll/12-death-valley-badwater-salt-flats.jpg - 98% of Earth’s crust is 8 minerals! - Most minerals in Earth are silicates (SiO 2 ) Ex) Sand & Quartz

4. 3.2 Mineral Identification 6 Physical properties 1. Color 2. Appearance 3. Hardness- How easily it can scratch 4. Luster- How light is reflected 5. Streak- Color of mineral when broken 6. Crystal System- Shape http://www.enchantedlearning.com/geology/rocks/pages/crystalsystems.shtml

5. Fracture- Mineral breaks jaggedly Ex) Quartz & Pyrite Cleavage- Mineral breaks smoothly Ex) Mica & Graphite Mohs Scale- Scale used to identify mineralsMohs Scale 3.3 Uses of Minerals Gems http://nmnhwww.si.edu/minsci/images/gallery/gem.htm http://nmnhwww.si.edu/minsci/images/gallery/gem.htm - Rare & beautiful - Some used for cutting, electronics

6. Ores - Mined for profit! Ex) Bauxite = Al, Magnetite = Fe Titanium - Lightweight, durable, doesn’t rust - Ilmenite & rutile- 2 ores mined for titanium