let’s talk minerals. warm up!! how are rocks and minerals related?

Let’s Talk Minerals

WARM UP!!

How are rocks and minerals related?

What is a mineral?

It is a naturally occurring, inorganic substance which has a definite chemical composition.

It must exist as a solid on Earth under normal conditions!

The atoms that make up the substance must be arranged in an orderly structure, so it has a definite crystal structure.

What is the opposite of this? Organic, man-made, random composition, and unorganized crystal structure

What causes minerals to have different physical properties?

the internal arrangement of their atoms

Minerals maybe made up of the same elements and have the same chemical formulas, but due to differences in the environments in which they formed, exhibit different physical properties!

Can you give an example of two minerals which have the same chemical composition

but different physical properties?

Graphite and diamonds are both made of carbon, and are sometimes found together. Diamonds are formed under extreme heat and pressure, graphite forms when the heat and pressure are not as intense.

Any questions so far?Any questions so far?

The Main Physical Properties Used to Identify Minerals

Color

a poor indicator

minerals can be multiple colors

many minerals are the same color

The Main Physical Properties Used to Identify Minerals

Streak

The streak of a mineral is the color it displays in finely

powdered form. The streak maybe completely different from the color of the hand specimen.

One of the simplest ways of determining the streak of a mineral is to rub a specimen across a piece of unglazed

porcelain known as a streak plate.

The Main Physical Properties Used to Identify Minerals

Streak

the powder form of a mineral

more reliable than color

The Main Physical Properties Used to Identify Minerals

Luster

how light reflects off a mineral

metallic non-metallic

looks like a metal

looks earthy, waxy, greasy or brilliant

The Main Physical Properties Used to Identify Minerals

Luster

how light reflects off a mineral

metallic non-metallic

Cleavage

The Main Physical Properties Used to Identify Minerals

the mineral breaks in a predictable patternbecause of its arrangement of atoms

Fracture

The Main Physical Properties Used to Identify Minerals

the mineral breaks randomly

Hardness

The Main Physical Properties Used to Identify Minerals

Is resistance to being scratched

It is NOT the same as breaking!

For example: You can break glass easily with steel.However, steel will not scratch glass.

Hardness

The Main Physical Properties Used to Identify Minerals

MOH’S SCALE OF HARDNESS

Hardness

Mineral Hardness

Mineral

1 (softest) 6

2 7

3 8

4 9

5 10 (hardest)

TALC

GYPSUMCALCITE

FLUORITE

APATITE

ORTHOCLASE

QUARTZTOPAZ

CORUNDUMDIAMOND

Minerals have a definite chemical composition.

There are two elements that, by mass,

make up most of the Earth’s crust

Minerals have a definite chemical composition.

These two elements combine to form compounds called

silicates (SiO4)

Minerals have a definite chemical composition.

They combine in a specific structure called a:

silicon-oxygen tetrahedra

All silicates have some form of SiO4 their chemical formula.

Ticket Out The DoorAnswer the Following Questions:

1. What are the five things required for something to be a mineral?

2. List 5 things that contain minerals.3. Is liquid mercury a mineral? Why or why

not?4. What two substances have the same

chemical make up but look completely different?

Tomorrow we will:Discuss mineral

identificationDiscuss the use of

minerals and rocks around us

Look at rock and mineral samples