Chapter 3 Minerals Lesson 1 What is a mineral? Pages 76-84.
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Transcript of Chapter 3 Minerals Lesson 1 What is a mineral? Pages 76-84.
Chapter Introduction
What are minerals and why are they useful?
http://www.redorbit.com/news/video/education_1/1112810933/what-is-a-mineral/
Chapter Introduction
SS#1 Sept. 24, 2013
Do you agree or disagree? Agree Disagree
A mineral is anything solid on Earth.
Some minerals form when water evaporates from Earth’s surface.
What is a mineral?
crystal solid chemical substance with a regular, repeating arrangement of its atoms
crystallization when particles dissolved in a liquid solidify to form crystals
lava molten rock that erupts onto Earth’s surface
magma molten rock material under Earth’s surface
Silicate a mineral group that has silicon and oxygen in its crystal structure
I can explain:• What is a mineral? (5 characteristics)• What the 6 crystal shapes are?• How minerals form? (3 ways plus an example)• What the common rock-forming minerals are?
(2 groups plus an example)
What is a mineral?
Lesson 1 Notes – What is a mineral?
• Minerals are naturally occurring, inorganic (non-living) solids that have a definite chemical composition and join together in an orderly crystal structure.
Mineralsnaturally occurring
inorganic
solidsdefinite chemical
composition
orderly crystal structure
• Minerals occur in many different shapes.
• When a crystal forms under the right conditions and has time to grow, it will develop a characteristic crystal shape.
• Most of the time, minerals grow in tiny clusters.
The Structure of Minerals
Crystal Shapes –HexagonalFour axes, three are equal in length and lie at an angle of 120° from each other.
Triclinic 3 axis, all unequal and none at 90° angles.
Orthorhombic All axis unequal in length, and 90° degrees from each other.
Crystal Forms –
Monoclinic All axis unequal in length. Two of them are at right angles to each other, while the third is lies at an angle other than 90°.
Tetragonal Three axes, two are equal in length, one is unequal.)
Isometric/Cubic All three axes are equal in length and at 90° degrees from each other.
• Minerals can crystallize from either hot or cool solutions.
• As water evaporates from a cool solution in a dry environment, solids crystallize out of the water and form minerals.
Example – halite
How do minerals form?
• Hot solutions are made when water flows through cracks in the earth’s crust into deep and hot environments.
• Sometimes hot solutions carry large concentrations of dissolved solids that eventually become valuable mineral deposits.
Example - gold
How do minerals form? (cont.)
• Minerals can also form from magma. Magma is molten material stored beneath Earth’s surface.
• When magma erupts on or near Earth’s surface, it is called lava or ash.
How do minerals form? (cont.)
• As lava above ground cools small crystals form quickly on or near Earth’s surface.
• Also as magma cools and crystallizes slowly below Earth’s surface, atoms and ions arrange themselves and form large mineral crystals.
Example – Quartz
How do minerals form? (cont.)
• The common rock-forming minerals are composed of combinations of elements that are abundant in Earth’s crust.
• Oxygen and silicon are the two most abundant elements in the crust.
The Structure of Minerals
The two main families of rock-forming minerals are the silicates and the nonsilicates.
• A silicate is a member of the mineral group that has silicon and oxygen in its crystal structure.
Example: Quartz, Feldspar, Olivine and Mica
• Nonsilicate minerals do not contain silicon.Example: Calcite and Halite
The Structure of Minerals (cont.)
• A mineral is a naturally occurring, inorganic solid with a definite chemical composition and crystalline form.
• Crystal shape reflects the internal arrangement of atoms or ions.
• The most common rock-forming minerals are silicates.
Lesson 1 – LR1
A. definiteB. indefiniteC. unstableD. stable
What type of chemical composition do minerals have?
Lesson 1 – LR2
A. mantleB. coreC. crustD. oceans
The common rock-forming minerals are composed of combinations of elements found in which part of the Earth?
A. evaporationB. disintegrationC. crystal growthD. crystallization
Which process occurs when particles dissolved in a liquid or gas solidify and form crystals?