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Agenda 2/25. Warm-Up: What materials went into making the desk you’re currently sitting in. Carefully consider your answer! Mineral Notes Mineral Webquest. Minerals of the Earth. What is a mineral?. DO you know what objects in this classroom are considered minerals? .
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Agenda 2/25 Warm-Up: What materials went into making the desk you’re currently sitting in. Carefully consider your answer! Mineral Notes Mineral Webquest
What is a mineral? DO you know what objects in this classroom are considered minerals? .
What is a mineral? Properties: • Solid • Cannot be a liquid or a gas • Naturally Occurring • Found in nature, not man-made • Inorganic • Is not alive and never was, non-living • Fixed composition • Has a chemical formula, most are formed from compounds of two or more elements, some minerals consist of one element ex. Au • Crystal Form • A definite structure in which atoms are arranged
Examples of minerals Gold Topaz Quartz Talc Diamond Just to name a few…
How are Minerals formed? • 1) Cooling of magma (hot, liquid rock and minerals inside the earth (from the mantle)) • Fast Cooling = Small crystals • Slow Cooling = large crystals
How are Minerals Formed? Elements dissolved in liquids (usually water) Water in a solution can dissolve only so much of a solid before the water becomes saturated. If solution becomes supersaturated (overfilled) with another substance, mineral crystals begin to form Ex: Gypsum deposits form from evaporated water
Physical Properties of Minerals(can be used to identify the mineral) Color • Can be misleading • Can vary with the type of impurities
Physical Properties of Minerals(can be used to identify the mineral) Luster • Surface reflection • metallic = shiny like metal • non-metallic = dull, non-shiny surface Pyrite has a metallic luster Calcite has a non-metallic luster
Physical Properties of Minerals(can be used to identify the mineral) 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
Streak…can help identify quartz BUT... http://www.childrensmuseum.org/geomysteries/cube/b3.html
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)
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
1. 4. 3. 2. Cleavage or Fracture?
Physical Properties of Minerals(can be used to identify the mineral) Other Properties • Specific gravity (*excellent clue to mineral’s identity) • Attraction to magnets • Bending of light • Reaction with hydrochloric acid • Smell & taste
Why is it important to learn about minerals? Rocks and minerals can tell us about the past and the formation of the Earth Many things we rely on come form minerals