Aim: What is a Mineral?

Do Now: Minerals are used in everyday life.

In your notebooks, try to brainstorm about ways minerals are used by you and me every

day.

I. Minerals:Minerals are classified as…a. Naturally occurring – Forms by natural

geologic processes.b. Solid substance c. Orderly crystalline structure – atoms

are arranged in an orderly and repetitive manner.

Fluorite

d. Definite chemical composition – most are made up of two or more elements.

e. Generally considered Inorganic – not living (exception calcite, which comes from living things).

Garnet

II. How do Minerals Form?

There are 3 major processes by which minerals from:

1. Crystallization crystallize = to form a crystal

- hot material (magma/lava) cools, - elements within the combine (come

together) and harden to form minerals.

Galena

2. Precipitates/Evaporites- solid substances are dissolved in water- When the water evaporates, these solids are left

behind to form crystals.

Like Rock Candy or the ring around your bathtub

Salt Flat - Halite

Limestone Cave

3. Hydrothermal Solutions

- Very hot solutions cause chemical reactions with existing minerals to form new minerals.

Pyrite Quartz

III. Tetrahedral Crystalline Structure

- Silicon and Oxygen combine to forma structure called the Silicon-OxygenTetrahedron.

**This structure is found in Quartz and makes it the most abundant mineral.

Review Questions:

1)What are the five characteristics of all minerals?

2)Where does the material come from to undergo crystallization?

3)Explain the process of the formation of a precipitate.

Minerals are naturally occurring, inorganic, solids, with definite crystal shape and definite

composition.

The material comes from the inside of the Earth or a volcanic eruption. The material has to be

extremely hot!

Material needs to be dissolved in water. Later, the water is evaporated leaving the mineral behind.

Solid materials can not be evaporated like water.

Aim: What properties do minerals have?

Do Now: How can a scientist tell the difference between different

minerals? List some of the properties you would look for to

classify a mineral.

Use your ESRT page 16 to help determine useful properties.

I. Properties of MineralsDepend on:

1) The chemical composition of the mineral. (the elements)

2) How the mineral’s atoms are arranged internally (structure).

**All mineral properties depend on the atoms that make-up the mineral**

Take out Page 16 of your ESRT

Non

-Met

allic

We will take notes on each section of this table

1. Color (least significant property)

- Small amounts of different elements (impurities) can give the same mineral different colors.

Quartz

Why is color the least significant property?

2. Streak - the color of a mineral in its powdered

form.

- found by rubbing a mineral across a streak plate (a piece of porcelain.)

- A minerals streak is identified as either;

Color – any color

Colorless – clear, white or no streak

3. Luster - describes how light is reflected from the

surface of a mineral.

Metallic vs. Non-Metallic

Pyrite Galena Sulfur Feldspar

What words would you use to describe non-metallic minerals?

4. Crystal Form- the visible expression of a mineral’s

internal arrangement of atoms.

CalciteQuartz

Garnet

5. Hardness

- the resistance of a mineral to being scratched.

- Mohs scale consists of 10 minerals arranged from 10 (hardest) to 1 (softest).

- determined using a glass plate.

How to find the hardness:

•Hold the glass plate flat on the table.

•Use a clean un-scratched surface.

•The mineral should be scratched against the glass plate once with some pressure.

1.If it scratches the glass, then the mineral is harder

2.If it doesn’t scratch the glass, then the mineral is softer.

Copy these last two for your notes on hardness.

6. Cleavage- the tendency of a mineral to break

(cleave) along flat, even surfaces.

- Minerals appear to have right angles, flat surfaces, boxed appearance.

CalciteMica

7. Fracture- the uneven breakage of a mineral.

Sulfur Quartz

8. Distinctive Properties of Minerals- Some minerals can be recognized by other

distinctive properties (magnetism, smell)

- Effervescence (bubbling)

using Hydrochloric Acid indicates the presence of calcium (Calcite.)

Closure

Take a blue lab from the back top bin. With your partner, begin to answer the vocabulary.

REMEMBER you are trying to do this from what you learned and recall, NOT from copying it out of

your book.