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Planet Earth
Minerals
2. Rocks and the Rock Cycle
3. Erosion
4. The Moving Crust
5. Earthquakes
6. Volcanoes
7. Mountains
8. Fossils
9. Geologic Time
10. Fossil Fuels
1.
Minerals
Topic 1
Minerals – Introduction
 Rocks contain naturally occurring, non-living substances
called minerals.
 Minerals are rare and are either:
 elements (made of 1 type of atom) or
 compounds (combinations of bonded atoms)
 Minerals are not only found in rocks, but they are also found in
your body, and dissolved in water (like iron and potassium)
 Mineral Uses - first 1:40
Think about it!
 How might you tell
these two minerals
apart?
 One is pyrite (fool’s
gold) the other is actual
gold – can you tell the
difference?
 Geology Kitchen Identifying Minerals
Identifying Minerals
Minerals can be identified 5 main ways:
1. Colour & Streak
2. Hardness
3. Shape & Crystals
4. Lustre
5. Cleavage & Fracture
(Chemical Properties, Transparency & Density)
Mineral Properties
Colour & Streak
 Some minerals can be identified by looking at the colour of
the surface.
 One Mineral may have several colours
 Corundum can be
white, blue or red,
depending on what
other elements are
present.
Colour & Streak
 When two different
minerals appear to
have the same
colour, streak can
be used to show the
colour of the
powder form of the
mineral
Hardness
 Fredrick Mohs was a
German scientist from the
early 1800’s
 He developed a scale of ten
minerals to show hardness
 Talc is the softest mineral –
similar to pencil lead
 Diamond is the hardest
mineral – used on surgical
scalpels, razor blades and
drill bits
Hardness – Mohs Scale
Hardness – Mohs Scale
Mineral
Mineral
Hardness
Hardness of
Common Objects
Talc
1
Soft pencil (1)
Gypsum
2
Fingernail (2.5)
Calcite
3
Copper (3.5)
Fluorite
4
Iron Nail (4.5)
Apatite
5
Glass (5.5)
Feldspar
6
Steel File (6.5)
Quartz
7
Porcelain Tile (7)
Topaz
8
Flint Sand Paper (7.5)
Corrundum
9
Emery Paper (9.0)
Diamon
10
Carborumdum Sandpaper
Shape & Crystals
 Crystals are the
building blocks of
minerals
 They are natural
structures with flat
faces, straight edges
 Most minerals will
grow into huge
crystal formations
Shape & Crystals
Lustre
 Lustre is the
shine of a
surface, or the
way it reflects or
absorbs light.
 Lustre is split
between metallic
and non-metallic
Lustre
Cleavage & Fracture
 Cleavage is when minerals split along the flat surfaces of the
crystals
 Fracture is when minerals break along uneven surfaces
 Mica has cleavage
because it breaks in
smooth flat sheets
Chemical Properties
 Some minerals will react with substances like acids
 Calcium carbonate (aka chalk) reacts with acids and produces
a new gas, so it bubbles
 Another chemical property is that metals corrode when
exposed to oxygen in the air.
 This is called rust, or oxidization
Transparency
 Minerals can also be identified by the amount
of light they let through. They can be:
 Transparent – see through
 Translucent – shadowy
 Opaque – no light passes through
Density
 Density relates to how many particles are in a
given amount of a mineral.
 If there are a lot, the mineral will seem quite
heavy compared to a less dense mineral
which can seem light.
 Some lava rock is so light
that it can float.
 This contributes to the
formation of volcanic
islands like Hawaii
Rocks & The Rock Cycle
Topic 2
The Rock Cycle
 There are three types of rocks
 Igneous
 Sedimentary
 Metamorphic
Igneous Rocks
 Igneous rock forms when hot magma or lava cool and solidify
 Magma is melted rock found below the Earth's crust
 Rocks made of magma are INtrusive igneous rocks
 Lava is molten rock that is on the earths surface (after
volcano)
 Rocks made of lava are EXtrusive igneous rocks
Igneous Rocks
 Cooling
magma and
lava will
create crystals
 The size of the
crystals
depends on
how fast the
rock cools
 The slower it
cools, the
larger the
crystals
Igneous Rocks - Intrusive
 Granite is an intrusive igneous rock
 Tiny crystals are visible in the rock
Igneous Rocks - Extrusive
 Obsidian is an extrusive igneous rock
 The crystals are too small to be seen because of how quickly
the rock cooled.
 Igneous Rocks
Sedimentary Rocks
 Sediment is small loose pieces of material like rocks,
minerals, and organic matter
 Sediment forms into sedimentary rock over time.
Sedimentary Rocks
 Sedimentary rock
is made up of
layers of
compressed
sediment,
cemented
together over time
 The cementation
happens when
certain minerals
dissolve in water
and bind the
sediment when it
dries.
Sedimentary Rocks
 75% of the rock
on the Earth’s
surface is
sedimentary
 Visible layers of
sedimentary
rock are called
strata
Sedimentary Rocks
 Types of sedimentary rock
include:
 Shale comes from fine clay or mud
 Sandstone comes from broken
down quartz
 Conglomerates are pebbles and
small stones cemented together
 Limestone is organic sedimentary
rock, containing fossils
 Sedimentary Rocks
Metamorphic Rocks
 Meta – Change
 Morph – shape/form
 Metamorphic rocks are those that have changed form
because of heat and pressure that have been applied to the
parent material.
Metamorphic rocks
 Shale  Slate  Schist
 Granite  Gneiss
 Limestone  Marble
 Metamorphic Rock
Metamorphic Rocks
The Rock Cycle
 Rocks are constantly
changing.
 The Rock Cycle varies
constantly as rocks are:
 Weathered
 Compression and





Cementation
Buried
Melted
Solidified
Sung
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