1. MINERALS Chapter 3

2. Section 1 What is it? 1. Naturally occurring- formed by processes on or outside Earth with NO input from humans 2. Inorganic- Not made by life processes 3. Element or Compound with a definite chemical composition EX: Halite (NaCl): (salt) distinctive taste that adds flavor to food 4. Orderly arrangement of atoms - All minerals are crystalline solids (Definite shape and volume)

3. STRUCTURE Crystal - solid with atoms arranged in orderly, repeating patterns 1. Some form from magma  hot melted rock below the Earth’s surface When magma cools: * Slowly  large crystals * Quickly  small crystals 2. Can form from solutions - Water evaporating - Too much of a substance is dissolved in water (H₂O)

4. Mineral Composition and Groups  Groups are defined by their composition (What they’re made up of) 1. Silicates (Most common): Contain silicon (Si), Oxygen (O), and 1 or more other elements EX: Quartz and Feldspar 2. Silicon (Si) and Oxygen (O) are the 2 most abundant elements in Earth’s crust. - They form the building blocks of many minerals in Earth’s crust and mantle

5. Glue in Crystal Shapes EX:  Cubic  Fluorite: Equal in size along all 3 dimensions  Tetragonal  Nickel: Longer on dimensions and shorter on the other (Rectangular)  Hexagonal  Quartz: 6 long sides, 2 faces  Orthorhombic  Sulfur: Dimensions are unequal in length (Brick-like)  Monoclinic  Gypsum: Unequal dimensions, 1 right angle, some oblique angles  Triclinic  Copper sulfate: Least amount of symmetry, unequal on ALL sides

7. MINERAL IDENTIFICATION Section 2: Physical Properties  Color and appearance are NOT enough to distinguish most minerals 1. Hardness- measure of how easily a mineral can be scratched - Mohs Scale  compares minerals hardness GLUE IN MOHS SCALE

9. 2. Luster- The way a mineral reflects light - Can be metallic (shinny metal) or nonmetallic (NOT shinny) - Nonmetallic lusters include: dull, pearly, silky, glassy EX: Quartz, calcite, halite, fluorite 3. Streak- The color of a mineral in powered form - Only useful if mineral is softer than a streak plate EX: Your pencil  Graphite leaves streak on your paper

10. 4. How do mineral break?  Cleavage- break along smooth, flat surfaces EX: Mica, halite  Fracture- Breaks with uneven, rough, or jagged surfaces EX: Quartz 5. Some minerals have unique properties involving light or magnesium

11. USES OF MINERALS Section 3 1. Gems- rare and beautiful minerals that are highly prized - Famous historical gems  Cullinan diamond  Hope diamond - Some have industrial applications in abrasive, lasers, and electronics EX: Rubies – produce specific types of laser light Quartz – electronics and time pieces (watches)

12. 2. Useful elements in minerals  Ore- a mineral or rock containing a substance that can be mined at a profit  Elements must be refined (purified) from ores (Separating out unwanted materials)  Some elements dissolve in fluids, travel through weaknesses in rocks, and in those weaknesses form deposits called vein mineral deposits.  Titanium- useful element derived(made from) from the minerals ilmenite and rutile - Used for: golf clubs, racing bikes, cars, wheelchairs, ect.