Minerals and Rocks

Rocks & Minerals

Earth and Space Science

Rock Cycle

1

Igneous Rocks

2

Sedimentary Rocks

4

Metamorphic Rocks

3

Minerals

5

Agenda

Erosion

Deposition

heat & pressure

melting

volcanic activity

Rock Cycle

Natural processes like erosion change rocks from one type
to another all the time. This process typically occurs very
slowly. The rock cycle has no beginning or end.

• Crystallization - as the magma cools, different crystals form

at different temperatures.

• Erosion & deposition - weathering wears down rocks on

Earth's surface into smaller pieces.

• Metamorphism - a rock that is exposed to extreme heat and

pressure but does not melt becomes a metamorphic rock.

Multiple Choice

_________ weathering wears down rocks on Earth's surface into smaller pieces

• Crystallization

• Erosion and deposition

• Metamorphism

• Volcanoes

Igneous
Rocks

Igneous rocks form from the cooling and hardening of molten
magna. These rocks can form by slowly cooling beneath the
surface or more quickly at the surface.

Extrusive Rock

intrusive Rock

Formed from:
Magna exits and cools above the Earth’s surface.

• Cools and solidifies almost instantly when it is exposed to the

relatively cool temperature of the atmosphere

• Grains are very fine or glassy
• Hot bubbles are often trapped in the lava, forming a bubbly,

vesicular texture

Formed when:
Magma inside Earth gets trapped

• Great globs of molten rock rise toward the surface
• Cools very slowly over many thousands or millions of years
• Grains are relatively large
• Corse grain texture

Multiple Choice

________ Rocks from the cooling and hardening of molten magma

• Igneous

• Sedimentary

• Metamorphic

• Minerals

Multiple Choice

Intrusive rock forms when magma inside the Earth gets trapped, causing large grain texture

• True

• False

Ultramafic Rocks

• High amounts of

magnesium and iron

• Low silica <40%

Mafic Rocks

• abundance of

ferromagnesian
minerals (with
magnesium and iron)

• dark minerals
• silica (45-50%)

intermediate rocks

• Between felsic and

mafic

• equal amounts of light

and dark minerals

• silica 55-65%

felsic rocks

• Light colored
• More silica (65-75%)
• Poor in iron and

magnesium

Composition

Groups refer to differing amounts of silica, iron, and magnesium found

in the minerals that make up the rocks

Multiple Choice

Composition is groups referring to different amounts of _____, iron, and magnesium

• Neon

• Hydrogen

• Oxygen

• Silica

texture

Depends on:

The amount of time magma/lava
takes to cool

rapidly cooling lava
will produce:

Aphanitic texture in which the
grains are too small to see with the
unaided eye

slowly cooling magma
will produce:

Phaneritic texture in which the
grains had a lot of time to grow and
can be seen with the unaided eye

igneous rock uses

and examples

cementation

Process of cementing minerals coating the sediment grains and gluing
them together into a fused rock

sedimentary
rocks

Sedimentary rocks form by the compaction and cementing
together of sediments. These rocks can be formed from
erosion and weathering of other rocks.

Erosion

A mechanical process, usually driven by water,, wind, gravity, or ice
which transports sediment (and soil) from the place of weathering

deposition

Happens when friction and gravity overcome the forces driving
sediment transport, allowing sediment to accumulate

compaction

Occurs when material continues to accumulate on top of the sediment
layer, squeezing the grains together and driving water out

Multiple Choice

_________ rocks form from compacting of deposition fragments until cementation occurs

• Igneous

• Sedimentary

• Metamorphic

• Minerals

Sediment

Pieces of rock that have been weathered and
possibly eroded away

examples

metamorphic
Rocks

Metamorphic rocks form when minerals in an existing rock are
changed by heat and pressure below the surface.

two ways rocks change

example one

Temperature (Heat) measures a substance’s energy - an increase in
temperature represents an increase in energy. Temperature changes
affect the chemical equilibrium or cation balance in minerals.

example two

Pressure is the force exerted over a unit area on a material. Like heat,
pressure can affect the chemical equilibrium of minerals in a rock. The
pressure that affects metamorphic rocks can be grouped into confining
pressures and directed stress.

Meta

Means: Change

Morphe

Means: Form

Multiple Select

Metamorphic rocks change by _______ and _______

• Heat

• Pressure

• Water

• Erosion

classification

foliated

non-foliated

A term used that describes minerals lined up in planes

Example: Schist

These do not have minerals that are lined in planes. They are
typically composed of just one mineral

Example: Quartzite

Multiple Choice

This is an example of non-foliated

• True

• False

minerals

Minerals are found everywhere, and almost any rock picked

up from the ground comprises minerals. They are
crystalline solids, meaning their atoms form a regular
repeating pattern.

silicate

minerals are built around a molecular ion called the silicon-oxygen tetrahedron.
Silicate minerals form the largest group of minerals on Earth

carbonate

The mineral group in which the carbonate ion is the building block

iron bearing

Mineral group composed of iron

types

Multiple Choice

Most rocks are made from minerals

• True

• False

Identifying
minerals

luster

How does the mineral look? Does it look metallic, glassy, earthy, silky, pearly?

cleavage

Breaking along specific lines in the mineral

streak

Examines the color of a powdered mineral and can be sen when a mineral sample is
scratched or scraped on an unglazed porcelain streak plate

hardness

Measures the ability of a mineral to scratch other substances using the Mohs Hardness
Scale

Scientists have identified
more than 4,000 minerals

in Earth’s crust.

Geology is the study of

rocks and Geologists are
the people who study them.

Multiple Choice

___________ is the study of rocks

• Geology

• Biology

• Physics

• Entomology

Sometimes, rocks from
space will land on Earth

and are called meteorites.

Mineralogists are the
scientists who study

minerals.

Earth’s moon is made out

of igneous rocks.

Multiple Choice

What type of rock is the moon made out of?

• Igneous

• Metamorphic

• Sedimentary

• Minerals

Thank
you!

Thank
you!