Chapter 3 & 4

Section 1: What Is A Mineral?

Is It A Mineral? It might be, if you can answer yes to the following questions: Is it a solid? Is it formed in nature? Is it nonliving material? Does it have a crystalline

structure?

A mineral is a naturally formed, inorganic solid with a crystalline structure.

http://www.flickr.com/photos/mheisel/2936798136/

Minerals can’t be gases or liquids!

No Air & No

Water

Crystalline materials made by people aren’t classified as minerals.

No Man Made Gemstones &

No Tires

A mineral is inorganic, meaning it isn’t made of living things. No Teeth & No

Bones

Minerals are crystals, which have a repeating inner structure that is often reflected in the shape of the crystal. Minerals generally have the same chemical composition throughout.

www.rblewis.net/.../WebQuests/atoms/atoms.jpg

Lets break it down: Minerals are made up

of Elements Elements are pure

substances that can’t be broken down into simpler substances

Atoms are the smallest part of an element

More than one type of atom stuck together is a compound

Most minerals are made up of compounds of different atoms

Halitez.about.com/d/chemistry/1/0/Y/6/halite.jpg

When atoms are held in a set structure it is called a crystal (or a crystalline structure)

http://www.flickr.com/photos/alishav/3221701134/

SILICATE

Minerals that contain Silicon and Oxygen

90% of Earth’s crust is made up of Silicate Minerals

Examples: Feldspar, Biotite Mica & Quartz

NONSILICATE

Minerals that do not contain Silicon & Oxygen

Examples: Native copper, Gold, Diamond, Calcite, Fluorite and Galena.

mrbarlow.files.wordpress.com/2009/02/diamond.jpg

Section 2: Identifying Minerals

Now that you know your sample is a mineral… we need to learn how to identify what mineral it is

Properties to ID Minerals Color Luster Streak Cleaving & Fracture Hardness Density Special Properties

Not a good indicator for IDExample: Pyrite (Fool’s Gold) has a

golden color normally – but when exposed to weather for a long time it turns black

www.3dchem.com/imagesofmolecules/pyrite2.jpg

Luster is the way a surface reflects light

Example: Dull or ShinyTypes of Luster:

Metallic/Glassy (Shiny) Submetallic (Dull) Nonmetallic (Dull)

www.thunderhealing.org/rock/anglesite.jpg

Streak is the color of a mineral’s powdered form

More reliable than Color because weathering doesn’t change the Streak Color

geology.csupomona.edu/alert/mineral/streak.jpg

Minerals break in certain ways depending on how the atoms are arranged Cleaving: When minerals break along

flat surfaces▪ Ex. Diamonds and Rubies

Fracture: When minerals break unevenly or irregularly▪ Ex. Quartz

Hardness refers to a mineral’s resistance to being scratched Example: Diamond is

the hardest mineral Moh’s Hardness Scale:

▪ Scale 1 – 10 Reference Minerals – p. 66

z.about.com/.../1/0/W/A/1/magnetitemassive.jpg

Density is how much matter there is in a given amount of space

Density of Water: 1 g/cm3

Specific Gravity = Object’s Density/Density of Water

The specific gravity of an unknown mineral can tell you it’s identity

Some minerals have unique properties: Taste (ex. Halite) Fluorescence (ex. Calcite & Fluorite) Chemical Reaction (ex. Calcite) Optical Properties (ex. Calcite) Radioactivity (ex. Radium & Uranium can

be detected in a mineral) Magnetism (ex. Magnetite & Pyrrhotite)

Section 3: The Formation & Mining of Minerals

Where a mineral is formed determines its properties

Minerals can form in many places Deep Below the Earth’s

surface, or at or near the Earth’s surface

http://www.flickr.com/photos/wolfgangstaudt/2241232829/

Minerals can form in: Evaporating Saltwater Limestones Metamorphic Rocks Hot-water Solutions Pegmatites Plutons

See pg. 68 – 69 in your text book and answer the following questions and put the answers on your note sheet!

This picture shows a mineral deposit at a geyser. Which of the 6 situations on page 68 and 69 explain its formation?

http://www.flickr.com/photos/jurek_durczak/312736434/

Name 3 minerals that are formed from magma.

http://www.flickr.com/photos/hurtubia/375483426/

How To Mine Minerals Two Possibilities:

Surface Mining▪ Ex. Open pits or quarries▪ Ex. Copper Ore &

Aluminum rich minerals Deep Mining

▪ Ex. Diamonds & Coal

Effects of Mining Minerals ores are turned

into common metals, as seen on pg. 71

Harmful Effects Destroys habit Waste gets into water Reclamation: turning the

mining land back into its original state after mining, required on public land, expensive & time consuming