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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 - PowerPoint PPT Presentation
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Chapter 1:
Minerals of the Earth’s
Crust
What is a Mineral?A Mineral has 4 Characteristics:1. Solid2. Crystalline Structure3. Non-Living4. Formed by Nature (not man
made)
What is a Mineral Made out of?Atoms - smallest particle that can exist of a
substanceElements - 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
Examples of Minerals
Most minerals can be classified based
upon their chemical composition (the
chemicals that make them up)
Composition of Minerals
• Minerals can be divided into 2 major groups:
1. Silicate minerals 2. Nonsilicate minerals
MINERALS
• Made of silicon and oxygen• 90% of Earth’s crust
Examples:–Feldspars –Biotite Mica–Quartz
SILICATE MINERALS
• Do not contain silicon and oxygenExamples include: •Copper•Gold•Silver
NONSILICATE MINERALS
Identifying Minerals
• Color• Luster• Streak• Cleavage• Fracture• Hardness – Mohs’ Scale 1-10, talc-
diamond• Density• Special Characteristics
Minerals can be identified by theircharacteristics.
• Minerals come in a variety of colors.
• Some colors are due to factors such as impurities and weather conditions.
1.) Color
Amethyst
1.) Color
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)
Metallic mineral
Semi-Metallic Mineral
Non-Metallic Minerals
3.) Streak• This is the color a mineral
appears when it is rubbed against an unglazed piece of porcelain
Streak Test
• The way that a mineral breaks. • Some break into
flat sheets, such as Mica• Others break in
angles, such as diamonds
4.) Cleavage
5.) Fracture• The tendency of some minerals to break unevenly along curved or irregular surfaces
• 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.
6.) Hardness
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.
Some minerals can be identified by othercharacteristics such as:• Fluorescence – glow under UV light• Chemical reaction – Fizzing when combined
w/acid• Optical Properties – Calcite will cause double
images• Radioactivity – Contain radium or uranium• Magnetism- attract iron• Taste – Salty, bitter, sour
8.) Special Properties
Fluorescence
Mining• Ore - Large enough deposit of an
element to gain a profit.
2 Types of Mining1.) Surface Mining• Removal of minerals or other materials at or
near the Earth’s surface. Examples: – Open pits– Strip mines– Quarries
• Materials mined in this way include copper ores and bauxite.
Open Pit
Strip Mine
2 Types of Mining2.) Deep Mining (Subsurface)• Drilling deep passageways below
Earth’s surface to reach the ore.
• Diamonds and coal are mined this way. – Can be VERY DANGEROUS!!!!
Deep Mining (Subsurface)
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 original state after the mining is completed.
• Reduces potential harmful effects of mining.• Very expensive and time consuming!• Mining gives us the minerals we need, but it
also creates problems.– The waste products from a mine can get into water
sources, polluting both surface water and ground water.
RECAPWhat are the 4 characteristics of a
mineral?• Solid, Crystalline Structure, Non-Living,
Formed by NatureWhat are the two groups that minerals aredivided into?• Silicate and NonsilicateWhat are the 3 silicate minerals?• Feldspars, Biotite Mica, QuartzWhat % of Earth’s crust contains silicate
minerals?• 90%