Earth Science 1.3 : Formation, Mining, and use of Minerals.

THE FORMATION, MINING, AND USE

OF MINERALS

Earth Science

Chapter 1.3

Objectives:

1. Describe the environments in which minerals forms

2. Compare the two types of mining

3. Describe two ways to reduce the effects of mining

4. Describe different uses for metallic and nonmetallic minerals

Formation of Minerals Minerals form in a variety of environments in

the Earth’s crust.Each has a different set of physical and chemical

conditions that determine the minerals’ properties Evaporating Salt Water

When a body of salt water dries up, minerals such as gypsum and halite are left behind

Metamorphic RocksWhen changes in pressure, temperature, or

chemical makeup alter a rock, metamorphism takes place

Minerals that form in metamorphic rock include:calcite, garnet, graphite, hematite, magnetite, mica,

and talc

LimestonesSurface water and groundwater carry dissolved

materials into lakes and seas, where they crystallized on the bottom

Minerals that form in this environment include: calcite and dolomite

limestone

dolomite

Hot-Water SolutionsGroundwater works its way downward and is

heated by magma, and then reacts with minerals to form a hot liquid solution

Dissolved metals and other elements crystallize out of the hot fluid to form new minerals, such as:gold, copper, sulfur, pyrite, and galena

PegmatitesAs magma rises upward from the Earth’s

crust, it can form teardrop-shaped bodies called pegmatites

Many gemstones such as:topaz and tourmaline, form in pegmatites

PlutonsAs magma rises upward through the crust, it

sometimes stops moving before it reaches the surface and cools slowly, forming millions of mineral crystals

Eventually, the entire magma body solidifies, forming minerals such as:mica, feldspar, magnetite, and quartz

Mining Many kinds of rocks and minerals must be

mined to extract the valuable elements they contain

Geologists use the term ore to describe a mineral deposit large enough and pure enough to be mined for profit

Rocks and minerals are removed from the ground by one of two methods

1. Surface Mining When mineral deposits are located at or

near the surface of the Earth, surface-mining methods are used to remove the minerals

Types of surface mines include:1. open pits

2. surface coal mines

3. quarries

2. Subsurface Mining

Methods are used when mineral deposits are located too deep within the Earth to be surface mined

Subsurface mining often requires that passageways be dug into the Earth to reach the ore

Responsible Mining Mining gives us the minerals we need, but it

may also create problems1. Can destroy or disturb the habitats of plants

and animals

2. Waste products from a mine may get into water sources, which pollutes surface water and ground water

1. One way to reduce the potential harmful effects of mining is to return the land to its original state after the mining is completedCalled reclamation

2. Reducing our need for minerals by recycling is another way to reduce the effects of mining

The Use of Minerals Metallic Minerals

good conductors of heat and electricityProcessed for various uses

1. Building aircraft

2. Automobiles

3. Communications

4. Electronic equipment

Examples of useful metallic minerals1. Gold

2. Silver

3. CopperAluminum – frameTitanium – handlebarsBeryllium – pedalsIron - spokes

Nonmetallic Mineralsgood insulators of electricityUses range from:

○ glass-making to producing computer chips

Example:Calcite is a major component of concrete,

which is used in building roads, buildings, bridges and other structures

Gemstoneshighly valued for their beauty and rarity, than for

their usefulnessImportant gemstones include

1. Diamond

2. Sapphire

3. Ruby

4. Emerald

5. Aquamarine

6. Topaz

7. tourmaline