Rocks and Minerals€¦ · Metamorphic Rocks Because their mineral grains grew together tightly...

Rocks and Minerals

What is this rock made up of?

Mica

Feldspar

Quartz

What is a mineral?

Mineral: solid, inorganic, pure substance which:

Occurs naturally

Has an ordered atomic structure which forms crystals.

There are 4000 known minerals on Earth.

What is a mineral?

Minerals rarely occur in a pure form.

They need to be mined.

When minerals are extracted from the

lithosphere, they are called ore.

Ore: rock containing a mineral that is mined

for profit

Please turn to page 303

A rock: A composition of minerals

Rocks are highly compacted minerals formed

through volcanic processes

They are not pure substances as they contain

many materials

Let’s explore some minerals

Commonly used minerals

Gold- used in jewellery

Sodium chloride - used as table salt

Beryllium- Found in emeralds

Pyrite- Used in alcohol preservation, also

known as fool’s gold

Magma: The one responsible

As molecules are being pushed upwards,

they will “clump” together.

The resulting clumping towards the Earth’s

surface solidifies the minerals.

Minerals closer to the surface contain

SMALLER more FINE molecules.

Crystals: The inner shape of

minerals

Highly crystallized structures

The resulting solid from solidification of

magma is seen under the microscope as fine

crystals.

Many minerals share the same crystalline

structure

Between a rock and a hard place

Rocks that cooled more SLOWLY contain

minerals solids that are larger

Which is why we can see the minerals clearly

Granite is an example

Between a rock and a hard place

Rocks that cooled more QUICKLY contain

minerals solids that are smaller

Which is why we cannot see the minerals

clearly

Basalt is an example

Igneous rock

Igneous rock is formed by magma (molten

rock) being cooled and becoming solid

Approximately 90% of Earth’s crust

Black, white or gray

Lots of holes

Black bread

Sedimentary rocks

Results from sediments and small particles

being carried away by erosion of the Earth

These sediments then accumulate over

million of years to give us LAYERS.

5% of Earth’s surface

Sedimentary rocks

They're usually the color of sediment, that is,

light brown to light gray.

They may preserve signs of life and surface

activity, like fossils, tracks, ripple marks and

so on.

Metamorphic rock

A rock that has been trapped under the

Earth’s crust for a long time. Often thousands

of years.

It is being chemically transformed by the heat

and pressure of the Earth’s crust

Examples are schist, slate and marble

Metamorphic Rocks

Because their mineral grains grew together tightly

during metamorphism, they're generally strong

rocks.

They're made of different minerals than other kinds

of rocks and have a wide range of color and luster.

They generally show signs of stretching or

squeezing, giving them a striped appearance.