Chapter 3: Minerals of the Earth’s Crust · Chapter 3 Section 1 What Is a Mineral? Two Groups of...

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Chapter 3: Minerals of the Earth’s Crust

Section 1: What is a Mineral?


Section 1 What Is a Mineral? Chapter 3

Mineral Structure

• A Mineral is a

• 1. naturally formed, (found in nature)

• 2. inorganic (Not made of once living things)

• 3. solid that has a . . .

• 4. definite crystalline structure.

• You can tell whether an object is a mineral by

asking the following four questions…



Mineral Structure, continued

• Is it a nonliving material?

• Is it a solid?

• Does it have a crystalline structure?

• Is it formed in nature?




• To understand what a crystalline structure is, you

need to know a little about the elements that make

up a mineral.

• Elements are pure substances that cannot be

separated or broken down into simpler substances

by chemical means. The elements are found on

the Periodic Table of Elements found on the back

wall and p. 794-795 in textbook.

•Solids: Black type; Liquids: Blue type; Gases: Red

(grouped by states of matter found at room temp.)



Elements




• Atoms and Compounds Minerals may be either

elements or compounds.

• A compound is a substance made of atoms of

two or more different elements joined by chemical

bonds.

Example:

Element: Na & Cl (two elements)

Compound: NaCl (one compound)




• A mineral that is composed of only one element is

called a native element.

• Gold and silver are examples of native elements.




• Solid, geometric forms of minerals produced by a

repeating pattern of atoms that is present through-

out the mineral are called crystals.

• A crystal’s shape is determined by the arrangement

of the atoms within the crystal.

• The arrangement of atoms in turn is determined by

the kinds of atoms that make up the mineral.


Crystals are orderly stacks of atoms. Here we see sodium atoms

(blue) and chlorine atoms (green) stacked in a way that makes

a microscopic cube. This cubic structure continues to grow

until your eyes can actually see a cubic crystal of salt. You

can't shape this crystal because when struck, the cube just

breaks into smaller cubes. Breakage is easier along the crystal

planes, which run same direction as the surface of the crystal.


**Watch Brain Pop Video:

CRYSTALS**

http://www.brainpop.com/science/earthsystem/crystals/



Two Groups of Minerals

• Minerals are divided into two groups based on their

chemical composition.

• Silicate minerals are minerals that contain a

combination of silicon (Si), oxygen(O), and one or

more metals.

• Examples of silicate minerals are quartz, feldspar,

and mica.



Two Groups of Minerals, continued

• Nonsilicate minerals are minerals that do not

contain compounds of silicon and oxygen. There

are six main classes of nonsilicate minerals.

• Native Elements

Gold & Silver

• Carbonates

Calcite

• Halides

Flourite

• Oxides

Corundum

• Sulfates

Gypsum

• Sulfides

Galena


Page 69 of textbook: Classes of Nonsilicate

Minerals

Chapter 3: Minerals of the Earth’s Crust · Chapter 3 Section 1 What Is a Mineral? Two Groups of...

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