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Chapter 1: Minerals of the Earth’s Crust. What is a Mineral?. A Mineral has 4 Characteristics : Solid Crystalline Structure Non-Living Formed by Nature (not man made). What is a Mineral Made out of?. Atoms - smallest particle that can exist of a substance
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What is a Mineral? A Mineral has 4 Characteristics: Solid CrystallineStructure Non-Living Formed byNature(not man made)
What is a Mineral Made out of? Atoms - smallest particle that can exist of a substance Elements - a pure substance that cannot easily be broken down Compounds - different elements combine to form larger substances Crystals- solid, geometric forms of minerals created by a repeating pattern of atoms Minerals
Composition of Minerals Most minerals can be classified based upon their chemical composition (the chemicals that make them up)
minerals • Minerals can be divided into 2 major groups: • Silicateminerals • Nonsilicate minerals
SILICATE Minerals • Made of silicon and oxygen • 90% of Earth’s crust Examples: • Feldspars • Biotite Mica • Quartz
NONSILICATE Minerals • Do notcontain silicon and oxygen Examples include: • Copper • Gold • Silver
Identifying Minerals Minerals can be identified by their characteristics. • Color • Luster • Streak • Cleavage • Fracture • Hardness – Mohs’ Scale 1-10, talc-diamond • Density • Special Characteristics
1.) Color • Minerals come in a variety of colors. • Some colors are due to factors such as impurities and weather conditions.
1.)Color Amethyst
2. Luster • The way a mineral reflects the light. A mineral’s luster can be: • Metallic (shiny) • Submetallic (a little shiny) • Nonmetallic (dull) • Vitreous (glassy) • Pearly (opalescent)
3.) Streak • This is the color a mineral appears when it is rubbed against an unglazed piece of porcelain Streak Test
4.) Cleavage • The way that a mineral breaks. • Some break into flat sheets, such as Mica • Others break in angles, such as diamonds
5.) Fracture • The tendency of some minerals to break unevenly along curved or irregular surfaces
6.) Hardness • This is a mineral’s resistance to being scratched. • Some minerals can be scratched easily, such as talc, while others are nearly impossible to scratch , such as diamonds.
7.) Density • This is how much matter is in a given space. • Mineral density varies • Example: • Gold’s density is much greater than mica’s.
8.) Special Properties Some minerals can be identified by other characteristics such as: • Fluorescence – glow under UV light • Chemical reaction – Fizzing when combined w/acid • Optical Properties – Calcite will causedouble images • Radioactivity – Contain radium or uranium • Magnetism- attract iron • Taste– Salty, bitter, sour
Mining • Ore - Large enough deposit of an element to gain a profit.
2 Types of Mining 1.) Surface Mining • Removal of minerals or other materials at or near the Earth’ssurface. Examples: • Open pits • Strip mines • Quarries • Materials mined in this way include copper ores and bauxite.
2 Types of Mining 2.) Deep Mining (Subsurface) Drilling deep passageways below Earth’s surface to reach the ore. Diamondsand coal are mined this way. Can be VERY DANGEROUS!!!!
Responsible Mining • Mining can disturb habitats of plants and animals. • Waste products from the removal of the ore can also cause pollution.
Reclamation • Reclamation – law since 1970 states that after mining you must return land to its originalstate after the mining is completed. • Reduces potential harmfuleffects of mining. • Very expensive and time consuming! • Mining gives us the mineralswe need, but it also creates problems. • The waste products from a mine can get into water sources, polluting both surface water and ground water.
RECAP What are the 4 characteristics of a mineral? • Solid, Crystalline Structure, Non-Living, Formed by Nature What are the two groups that minerals are divided into? • Silicate and Nonsilicate What are the 3 silicate minerals? • Feldspars, Biotite Mica, Quartz What % of Earth’s crust contains silicate minerals? • 90%