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Minerals. Chapter 4 Section 1&2 EQ: What are the main characteristics of a mineral? What properties are used to identify minerals?. What is a Mineral?. Naturally-formed solid substance with a crystal structure. Pyromorphite. What do all minerals have in common?. All:
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Minerals Chapter 4 Section 1&2 EQ: What are the main characteristics of a mineral? What properties are used to identify minerals?
What is a Mineral? • Naturally-formed solid substance with a crystal structure Pyromorphite
What do all minerals have in common? All: • Are formed by natural processes. • Inorganic- Never alive or made from living things. • Have a definite volume and shape • Solids with a unique chemical makeup • Are made up of particles that are arranged in a pattern that is repeated over and over (called a CRYSTAL)
Groups of Minerals • Minerals are grouped by the elements they are made of. Beryl (Emerald) Calcite Amethyst
MICA Quartz
Silver Copper Diamond Gold Iron Ruby
BariteBaSo4 Barite on CalciteBaSo4 / CaCO3
How do minerals form? • 1) Cooling of magma (hot, liquid rock and minerals inside the earth (from the mantle)) • Fast Cooling = No Crystals (mineraloids) • Medium Cooling = small crystals • Slow Cooling = large crystals
How do minerals form? • 2) Elements dissolved in liquids (usually 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 http://www.childrensmuseum.org/geomysteries/cube/b4.html